We Keep Coding

Alert box displays NaN after the desired pop up

Afer going through all the suggestions, this is what i have come with. But if I am having something like $100 instead of 100, is there anyway i can covert it into number ?
var selectedRows = document.getElementsByClassName('selected');
limit = 0; //set limit
checkboxes = document.querySelectorAll('.checkboxdiv input[type="checkbox"]');
function checker(elem) {
if (elem.checked) {
limit++;
} else {
limit--;
}
for (i = 0; i < checkboxes.length; i++) {
if (limit == 2) {
if (!checkboxes[i].checked) {
checkboxes[i].disabled = true;
}
} else {
if (!checkboxes[i].checked) {
checkboxes[i].disabled = false;
}
}
}
}
for (i = 0; i < checkboxes.length; i++) {
checkboxes[i].onclick = function() {
checker(this);
}
}
function inputChanged(event) {
event.target.parentElement.parentElement.className =
event.target.checked ? 'selected' : '';
}
function Calculate() {
var cal = 0;
for (var i = 0; i < selectedRows.length-1; i++) {
cal = Number(selectedRows[i].textContent - selectedRows[i+1].textContent);
}
alert(Number(cal))
}
background-color: yellow;
<table class="checkboxdiv">
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>$100</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>$20</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>$40</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>$21</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>$12</td>
</tr>
</table>
<button onclick="Calculate()">Calculate</button>
Hi I am trying to calculate the difference between two values of the checkbox and displaying the popup (alert box). I am getting 2 issues here
After getting the result popup I am getting one more pop up which says Nan. How do i remove that?
I want to limit the number of selected checkbox to 2, once 2 checkboxes are selected remaining should be disabled I have written the code to if length is greater than 2, checkbox should be disabled but that is not working.
var selectedRows = document.getElementsByClassName('selected');
if(selectedRows.length>2){
document.getElementById("mycheck").disabled = true;
}
function inputChanged(event) {
event.target.parentElement.parentElement.className =
event.target.checked ? 'selected' : '';
}
function Calculate() {
for (var i = 0; i < selectedRows.length; ++i) {
alert(selectedRows[i]?.textContent.trim() - selectedRows[i+1]?.textContent.trim());
}
}
.selected {
background-color: yellow;
}
<table>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>100</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>20</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>40</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>21</td>
</tr>
<tr>
<td>
<input id = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>12</td>
</tr>
</table>
<button onclick="Calculate()">Calculate</button>

First of all the attribute id should be unique in a document, you can use class instead.
You should access the selectedRows inside the function Calculate.
Since you want to limit the number of selected checkbox to 2 your condition should be .length > 1.
You can try the following way:
function inputChanged(event) {
//get all checked
var mycheck = document.querySelectorAll('.mycheck:checked');
//get all unchecked
var mycheckNot = document.querySelectorAll('.mycheck:not(:checked)');
if(mycheck.length > 1){
//disabled all unchecked
for (var i = 0; i < mycheckNot.length; i++) {
mycheckNot[i].disabled = true;
}
}
else{
//enable all unchecked
for (var i = 0; i < mycheckNot.length; i++) {
mycheckNot[i].disabled = false;
}
}
event.target.parentElement.parentElement.className =
event.target.checked ? 'selected' : '';
}
function Calculate() {
//get all selected
var selectedRows = document.getElementsByClassName('selected');
var sum = 0 ;
for (var i = 0; i < selectedRows.length; i++) {
//convert the value to number and sum them up
sum += Number(selectedRows[i].textContent)
}
alert(sum);
}
.selected {
background-color: yellow;
}
<table>
<tr>
<td>
<input class = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>100</td>
</tr>
<tr>
<td>
<input class = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>20</td>
</tr>
<tr>
<td>
<input class = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>40</td>
</tr>
<tr>
<td>
<input class = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>21</td>
</tr>
<tr>
<td>
<input class = "mycheck" type="checkbox" onchange="inputChanged(event)" />
</td>
<td>12</td>
</tr>
</table>
<button onclick="Calculate()">Calculate</button>

How I can put the required input fields in my Js code

How I can put the required fields in my Js code
I set required = true in xml view but it does blocker all the form
how to add required for the js code jQuery
this my code jQuery :
// table course
jQuery(document).ready(function() {
var id = 0;
var cr = 0;
jQuery("#addcourserow").click(function() {
id++;
var row = jQuery('.courserow tr').clone(true);
var c = 1;
row.find("input").each(function(){
if (c === 1) {
$(this).attr('name','course_name_'+id);
}
else if (c === 2) {
$(this).attr('name','course_duration_'+id);
}
else if (c === 3) {
$(this).attr('name','course_date_'+id);
}
c++;
});
row.appendTo('#CourseTable');
return false;
});
$('.remove').on("click", function() {
$(this).parents("tr").remove();
});
});
and this my XML
<!-- Course -->
<table id="CourseTable">
<thead>
<th>name</th>
<th>duration</th>
<th>date</th>
</thead>
<tr id="tr_course">
<td><input type="text" name="course_name_1" id="course_name"/></td>
<td><input type="text" name="course_duration_1" id="course_duration"/></td>
<td><input type="date" name="course_date_1" id="course_date" /></td>
<td><button class="remove">Remove</button></td>
</tr>
</table>
<input type="button" id="addcourserow" value="add row" />
<table class="courserow" style="display:none">
<tr>
<td><input type="text" id="course_name" /></td>
<td><input type="text" id="course_duration"/></td>
<td><input type="date" id="course_date"/></td>
<td><button class="remove">Remove</button></td>
</tr>
</table>
</div>
I added here in codepen

Please consider the following code.
$(function() {
var id = 0;
var cr = 0;
var names = [
"course_name",
"course_duration",
"course_date"
];
$("#addcourserow").click(function() {
var row = $('#course-row-template tr').clone(true);
id++;
var c = 0;
row.find("input").each(function() {
var inpId = $(this).attr("id") + "_" + id;
$(this).attr({
id: inpId,
name: names[c++] + "_" + id
}).prop("required", true);
console.log($(this));
});
row.appendTo('#CourseTable');
return false;
});
$('.remove').on("click", function() {
$(this).parents("tr").remove();
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
<table id="CourseTable">
<thead>
<th>name</th>
<th>duration</th>
<th>date</th>
</thead>
<tr id="tr_course">
<td><input type="text" id="course_name_0" /></td>
<td><input type="text" id="course_duration_0" /></td>
<td><input type="date" id="course_date_0" /></td>
<td><button class="remove">Remove</button></td>
</tr>
</table>
<input type="button" id="addcourserow" value="Add New Row" />
<table id="course-row-template" style="display:none">
<tr>
<td><input type="text" id="course_name" /></td>
<td><input type="text" id="course_duration" /></td>
<td><input type="date" id="course_date" /></td>
<td><button class="remove">Remove</button></td>
</tr>
</table>
This will ensure that each <input> has a unique ID and name. It also adds the required property to each of them.
Hope that helps.

i find answer
jQuery(document).ready(function() {
var id = 0;
jQuery("#addcourserow").click(function() {
id++;
var row = jQuery('.courserow tr').clone(true);
var c = 1;
row.find("input").each(function(){
if (c === 1) {
$(this).attr('name','course_name_'+id).prop("required", true);
}
else if (c === 2) {
$(this).attr('name','course_duration_'+id).prop("required", true);
}
else if (c === 3) {
$(this).attr('name','course_date_'+id).prop("required", true);
}
c++;
});
row.appendTo('#CourseTable');
return false;
});
$('.remove').on("click", function() {
$(this).parents("tr").remove();
});
});
and i add required in my Xml
<table id="CourseTable">
<thead>
<th>name</th>
<th>duration</th>
<th>date</th>
</thead>
<tr id="tr_course">
<td><input type="text" name="course_name_1" id="course_name" required="required"/></td>
<td><input type="text" name="course_duration_1" id="course_duration" required="required"/></td>
<td><input type="date" name="course_date_1" id="course_date" required="required"/></td>
<td><button class="remove">Remove</button></td>
</tr>
</table>

Error within HTML Code

I am in the process of writing a webpage. I have everything done that is needed, however, when you enter any quantity over 30 it will make the id = "shipping" color red. It does this but it does it for anything less than 30 as well. Also I am having trouble with my submit button sending off to a server/url. Any help is appreciated! I will attach my code!
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title> Widgets R' Us </title>
<style>
table,
td {
border: 1px solid black;
}
</style>
<script type="text/javascript">
//Check if non -number or a negative number
function realNumber() {
var qty1 = document.getElementById("Quantity1").value;
var qty2 = document.getElementById("Quantity2").value;
var qty3 = document.getElementById("Quantity3").value;
//isNaN is a predetermined function
if ((isNaN(qty1) || qty1 < 0) || (isNaN(qty2) || qty2 < 0) || (isNaN(qty3) || qty3 < 0)) {
alert("The quantity given is not a real number or is a negative number!");
return false; //Will not allow for data to go to server.
} else {
return true;
}
}
function total() {
var p1 = document.getElementById("Price1").value; //Value is referenced to the input tag
var p2 = document.getElementById("Price2").value;
var p3 = document.getElementById("Price3").value;
var qty1 = document.getElementById("Quantity1").value;
var qty2 = document.getElementById("Quantity2").value;
var qty3 = document.getElementById("Quantity3").value;
var over = qty1 + qty2 + qty3;
if (realNumber()) {
var totals = (p1 * qty1) + (p2 * qty2) + (p3 * qty3);
var yes = (totals).toFixed(2);
document.getElementById("ProductTotal").innerHTML = "$" + yes;
if (over > 30) {
document.getElementById("shipping").style.color = "red";
} else {
document.getElementById("shipping").style.color = "black";
}
}
}
function checkOut() {
if (total()) {
if ((document.getElementById("shipping").style.color == "red") &&
(document.getElementById("extra").checked)) {
return true;
}
}
return false;
}
</script>
</head>
<body>
<div>
<h1><b><big> Widgets R' Us </b></strong>
</h1>
<h2><b> Order/Checkout </b></h2>
<form name "widgets" onsubmit="return checkOut();" action="https://www.reddit.com/" method="get">
<div id="mainTable">
<table>
<tr>
<td>Widget Model:</td>
<td>37AX-L
<td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$12.45 <input type="hidden" id="Price1" name="Price1" value="12.45" /</td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity1" name="Quantity1" value="0" /</td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Widget Model:</td>
<td>42XR-J</td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$15.34 <input type="hidden" id="Price2" name="Price2" value="15.34" /></td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity2" name="Quantity2" value="0" /></td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Widget Model:</td>
<td>93ZZ-A</td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$28.99 <input type="hidden" id="Price3" name="Price3" value="28.99" /></td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity3" name="Quantity3" value="0" /></td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Product Total:</td>
<td>
<p id="ProductTotal"> 0 </p>
</td>
</tr>
<tr>
<td> <input type="checkbox" id="extra" name="extra"> </td>
<td>
<p id="shipping">If the quantity exceeds 30 units, there will be extra shipping!</p>
</td>
</tr>
</table>
</div>
<tr>
<td> <input type="Submit" value="Submit" /> </td>
<td> <input type="button" value="Calculate" onClick="total()" /> </td>
</tr>
</form>
</body>
</html>

Problem with your values qty1,qty2,qty3. these values are reading as string. so instead of addding these values , its concatinating the strings. replace
var qty1 = document.getElementById("Quantity1").value;
var qty2 = document.getElementById("Quantity2").value;
var qty3 = document.getElementById("Quantity3").value;
with
var qty1 = parseInt(document.getElementById("Quantity1").value);
var qty2 = parseInt(document.getElementById("Quantity2").value);
var qty3 = parseInt(document.getElementById("Quantity3").value);
It will Solve your problem with 'Red'.
For the submit button, function total() is not returning anything. so change something like
function total() {
var p1 = document.getElementById("Price1").value; //Value is referenced to the input tag
var p2 = document.getElementById("Price2").value;
var p3 = document.getElementById("Price3").value;
var qty1 = parseInt(document.getElementById("Quantity1").value);
var qty2 = parseInt(document.getElementById("Quantity2").value);
var qty3 = parseInt(document.getElementById("Quantity3").value);
var over = qty1 + qty2 + qty3;
if (realNumber()) {
var totals = (p1 * qty1) + (p2 * qty2) + (p3 * qty3);
var yes = (totals).toFixed(2);
document.getElementById("ProductTotal").innerHTML = "$" + yes;
if (over > 30) {
document.getElementById("shipping").style.color = "red";
return true;
} else if(over>0) {
document.getElementById("shipping").style.color = "black";
return true;
}else{
document.getElementById("shipping").style.color = "black";
return false;
}
}
}
and checkout() as
function checkOut() {
if (total()) {
if (((document.getElementById("shipping").style.color == "red") &&
(document.getElementById("extra").checked))||
(document.getElementById("shipping").style.color != "red")) {
return true;
}
}
return false;
}

Replace
var over = qty1 + qty2 + qty3;
With
var over = parseInt(qty1) + parseInt(qty2) + parseInt(qty3);

There were some minor HTML errors but the real issue is that numeric strings were being concatenated. So, to get the quantity values you need to use parseInt() to extract the integer value so that math is performed instead of string concatenation. Also, it's a little odd that the user has to click the Calculate Button in order to see a total. The button does work correctly, but is this what you really want?
One more thing, as tempting as it may be to directly alter the color of elements with JavaScript, in terms of keeping the code more robust, it is preferable to simply change the class name as the code does in this example since I created two classes in the CSS for this purpose.
The form now submits as long as the checkbox is unchecked and the units do not exceed 30. I changed the method to "post" and adjusted the true/false return statements in checkOut(). Note when data is submitted using the POST method, then no form data appears appended to the URL; for more info see here. I also altered the totals() function so that now it returns a value, namely the total price.
var d = document;
d.g = d.getElementById;
var qty = [0, 0, 0, 0];
var shipping = d.g("shipping");
function realNumber() {
var qtyInvalid = [0, 0, 0, 0];
for (let i = 1, max = qtyInvalid.length; i < max; i++) {
qtyInvalid[i] = (isNaN(qty[i]) || qty[i] < 0);
}
if (qtyInvalid[1] || qtyInvalid[2] || qtyInvalid[3]) {
console.log("The quantity given is not a real number or is a negative number!");
return false;
}
return true;
}
function total() {
var over = 0;
var price = [0, 0, 0, 0];
for (j = 1, max = price.length; j < max; j++) {
price[j] = d.g("Price" + j + "").value;
qty[j] = d.g("Quantity" + j + "").value;
}
var totals = 0;
var yes = 0;
const radix = 10;
for (q = 1, max = qty.length; q < max; q++) {
over += parseInt(qty[q], radix)
}
//console.log(over);
if (!realNumber()) {
return false;
}
for (let k = 1, max2 = price.length; k < max2; k++) {
totals += (price[k] * qty[k]);
}
yes = (totals).toFixed(2);
d.g("ProductTotal").innerHTML = "$" + yes;
shipping.className = (over > 30) ? "red" : "black";
return totals;
} // end total
function checkOut() {
var retval = false;
var shippingIsRed = (shipping.className == "red");
var extraChecked = d.g("extra").checked;
if ( total() ) {
retval = (!shippingIsRed && !extraChecked)? true : false;
}
return retval;
} //end checkout
h1 {
font: 200% Arial, Helvetica;
font-weight: bold;
}
h2 {
font-weight: bold;
}
table,
td {
border: 1px solid black;
}
p.red {
color: #f00;
}
p.black {
color: #000;
}
<div>
<h1>Widgets R' Us</h1>
<h2>Order/Checkout</h2>
<form name="widgets" onsubmit="return checkOut()" action="https://www.example.com/" method="post">
<div id="mainTable">
<table>
<tr>
<td>Widget Model:</td>
<td>37AX-L
<td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$12.45 <input type="hidden" id="Price1" name="Price1" value="12.45" </td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity1" name="Quantity1" value="0" </td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Widget Model:</td>
<td>42XR-J</td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$15.34 <input type="hidden" id="Price2" name="Price2" value="15.34"></td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity2" name="Quantity2" value="0"></td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Widget Model:</td>
<td>93ZZ-A</td>
</tr>
<tr>
<td>Price per Unit:</td>
<td>$28.99 <input type="hidden" id="Price3" name="Price3" value="28.99"></td>
</tr>
<tr>
<td>State:</td>
<td>Regular</td>
</tr>
<tr>
<td>Quantity:</td>
<td> <input type="text" id="Quantity3" name="Quantity3" value="0"></td>
</tr>
</table>
<tr>
<td> </td>
<td> </td>
</tr>
<table>
<tr>
<td>Total Price:</td>
<td>
<p id="ProductTotal"> 0 </p>
</td>
</tr>
<tr>
<td> <input type="checkbox" id="extra" name="extra"> </td>
<td>
<p id="shipping" class="black">If the quantity exceeds 30 units, there will be extra shipping!</p>
</td>
</tr>
</table>
</div>
<tr>
<td> <input type="Submit" value="Submit" /> </td>
<td> <input type="button" value="Calculate" onClick="total()"> </td>
</tr>
</form>
I also removed some unnecessary repetitive code that fetches the quantity values, taking advantage of JavaScript closures and for-loops.

Clone a row in an HTML table and call JavaScript function with the new row

I have a table which has one row in which I multiply two fields, namely quantity and rate/quantity, to get the product total. I have provided a button to add a new row which basically clones the 1st row. Now I want the cloned row to also have the same product as the 1st row. I have tried the following code:
<!DOCTYPE html>
<html>
<h3 align="center">K J Somaiya College Of Engineering, Vidyavihar, Mumbai-400 077</h3>
<h3 align="center">Department Of Information Technology</h3>
<body>
<script>
function WO1() {
var qty = document.getElementById('qty').value;
var price = document.getElementById('price').value;
answer = (Number(qty) * Number(price)).toFixed(2);
document.getElementById('totalprice').value = answer;
}
function WO2() {
var qty = document.getElementById('qty1').value;
var price = document.getElementById('price1').value;
answer = (Number(qty) * Number(price)).toFixed(2);
document.getElementById('totalprice1').value = answer;
}
function WO3() {
var qty = document.getElementById('qty2').value;
var price = document.getElementById('price2').value;
answer = (Number(qty) * Number(price)).toFixed(2);
document.getElementById('totalprice2').value = answer;
}
</script>
<script>
function validateNumbe()
{
var x=document.getElementById("floor").value;
if (x==null || x=="")
{
alert("Floor must be entered");
return false;
}
}
function validateN()
{
var x=document.getElementById("lab").value;
if (x==null || x=="")
{
alert("Laboratory Name must be entered");
return false;
}
}
function validateNumb()
{
var x=document.getElementById("room").value;
if (x==null || x=="")
{
alert("Room No must be entered");
return false;
}
}
function validateNum()
{
var x=document.getElementById("labi").value;
if (x==null || x=="")
{
alert("Name of Laboratory Incharge must be entered");
return false;
}
}
function validateNu()
{
var x=document.getElementById("year").value;
if (x==null || x=="")
{
alert("Budget for the year must be entered");
return false;
}
}
</script>
<table width="100%" cellspacing="10">
<tr>
<td align="left">Date:<input type="date" name="date"/></td>
<td align="right">Floor: <input type="text" id="floor" onchange="validateNumbe()"
onblur="validateNumbe()"/> </td>
</tr>
<tr>
<td align="left">Laboratory Name: <input type="text" id="lab" onchange="validateN()"
onblur="validateN()"/></td>
<td align="right">Room no: <input type="text" id="room" onchange="validateNumb()"
onblur="validateNumb()"/></td>
</tr>
<tr>
<td align="left">Name of Laboratory Incharge: <input type="text" id="labi"
onchange="validateNum()" onblur="validateNum()"/></td>
<td align="right">Budget for the year: <input type="text" id="year" onchange="validateNu()"
onblur="validateNu()"/></td>
</tr>
</table>
<h3 align="left"><b>Computer</b><h3>
<table id="POITable" border="1" width="100%">
<tr>
<td style="width:10%">Sr No.</td>
<td>Item Description</td>
<td>Quantity</td>
<td>Rate(Inclusive of Taxes)</td>
<td>Total Cost</td>
</tr>
<tr>
<td>1</td>
<td><textarea rows="4" cols="50" name="comp_item"></textarea></td>
<td><input type='text' name='Quantity' id='qty' class="qty" placeholder='Qty' /></td>
<td><input type='text' name='Rate' id='price' class="price" placeholder='Price (£)'
onChange="WO1()" /></td>
<td><input type='text' name='Total' id='totalprice' class="price" placeholder='Total
Price (£)' /></td>
</tr>
</table>
<input type="button" id="addmorePOIbutton" value="Add New Row"/>
<h3 align="left"><b>Equipment</b><h3>
<table id="POITable1" border="1" width="100%">
<tr>
<th style="width:10%">Sr No.</th>
<th>Item Description</th>
<th>Quantity</th>
<th>Rate(Inclusive of Taxes)</th>
<th>Total Cost</th>
</tr>
<tr>
<td>1</td>
<td><textarea rows="4" cols="50" name="comp_item"></textarea></td>
<td><input type='text' name='Quantity' id='qty1' class="qty" placeholder='Qty' /></td>
<td><input type='text' name='Rate' id='price1' class="price" placeholder='Price (£)'
onChange="WO2()" /></td>
<td><input type='text' name='Total' id='totalprice1' class="price" placeholder='Total
Price (£)' /></td>
</tr>
</table>
<input type="button" id="addmorePOIbutton1" value="Add New Row"/>
<h3 align="left"><b>Furniture</b><h3>
<table id="POITable2" border="1" width="100%">
<tr>
<th style="width:10%">Sr No.</th>
<th>Item Description</th>
<th>Quantity</th>
<th>Rate(Inclusive of Taxes)</th>
<th>Total Cost</th>
</tr>
<tr>
<td>1</td>
<td><textarea rows="4" cols="50" name="comp_item"></textarea></td>
<td><input type='text' name='Quantity' id='qty2' class="qty" placeholder='Qty' /></td>
<td><input type='text' name='Rate' id='price2' class="price" placeholder='Price (£)'
onChange="WO3()" /></td>
<td><input type='text' name='Total' id='totalprice2' class="price" placeholder='Total
Price (£)' /></td>
</tr>
</table>
<input type="button" id="addmorePOIbutton2" value="Add New Row"/>
<script>
( function() { // Prevent vars from leaking to the global scope
var formTable = document.getElementById('POITable');
var newRowBtn = document.getElementById('addmorePOIbutton');
newRowBtn.addEventListener('click', insRow, false); //added eventlistener insetad of inline
onclick-attribute.
function insRow() {
var new_row = formTable.rows[1].cloneNode(true),
numTableRows = formTable.rows.length;
// Set the row number in the first cell of the row
new_row.cells[0].innerHTML = numTableRows;
numTableRows=numTableRows - 1;
var inp1 = new_row.cells[1].getElementsByTagName('textarea')[0];
inp1.name += numTableRows;
inp1.value = '';
var inp2 = new_row.cells[2].getElementsByTagName('input')[0];
inp2.name += numTableRows;
inp2.value = '';
var inp3 = new_row.cells[3].getElementsByTagName('input')[0];
inp3.name += numTableRows;
inp3.value = '';
var inp4 = new_row.cells[4].getElementsByTagName('input')[0];
inp4.name += numTableRows;
inp4.value = '';
// Append the new row to the table
formTable.appendChild( new_row );
}
var formTable1 = document.getElementById('POITable1');
var newRowBtn1 = document.getElementById('addmorePOIbutton1');
newRowBtn1.addEventListener('click', insRow1, false); //added eventlistener insetad of inline
onclick-attribute.
function insRow1() {
var new_row = formTable1.rows[1].cloneNode(true),
numTableRows = formTable1.rows.length;
// Set the row number in the first cell of the row
new_row.cells[0].innerHTML = numTableRows;
numTableRows=numTableRows - 1;
var inp1 = new_row.cells[1].getElementsByTagName('textarea')[0];
inp1.name += numTableRows;
inp1.value = '';
var inp2 = new_row.cells[2].getElementsByTagName('input')[0];
inp2.name += numTableRows;
inp2.value = '';
var inp3 = new_row.cells[3].getElementsByTagName('input')[0];
inp3.name += numTableRows;
inp3.value = '';
var inp4 = new_row.cells[4].getElementsByTagName('input')[0];
inp4.name += numTableRows;
inp4.value = '';
// Append the new row to the table
formTable1.appendChild( new_row );
}
var formTable2 = document.getElementById('POITable2');
var newRowBtn2 = document.getElementById('addmorePOIbutton2');
newRowBtn2.addEventListener('click', insRow2, false); //added eventlistener insetad of inline
onclick-attribute.
function insRow2() {
var new_row = formTable2.rows[1].cloneNode(true),
numTableRows = formTable2.rows.length;
// Set the row number in the first cell of the row
new_row.cells[0].innerHTML = numTableRows;
numTableRows=numTableRows - 1;
var inp1 = new_row.cells[1].getElementsByTagName('textarea')[0];
inp1.name += numTableRows;
inp1.value = '';
var inp2 = new_row.cells[2].getElementsByTagName('input')[0];
inp2.name += numTableRows;
inp2.value = '';
var inp3 = new_row.cells[3].getElementsByTagName('input')[0];
inp3.name += numTableRows;
inp3.value = '';
var inp4 = new_row.cells[4].getElementsByTagName('input')[0];
inp4.name += numTableRows;
inp4.value = '';
// Append the new row to the table
formTable2.appendChild( new_row );
}
})();
function myfun()
{
var lun= document.getElementById('POITable').rows.length;
document.getElementsByName("len")[0].value = lun-1;
var lun1= document.getElementById('POITable1').rows.length;
document.getElementsByName("len1")[0].value = lun1-1;
var lun2= document.getElementById('POITable2').rows.length;
document.getElementsByName("len2")[0].value = lun2-1;
}
function myFunction()
{
window.print();
}
</script>
<input type="hidden" name="len" value="1">
<input type="hidden" name="len1" value="1">
<input type="hidden" name="len2" value="1">
<table width="100%">
<tr>
<td><br><br><br></td>
<td><br><br><br></td>
<td><br><br><br></td>
</tr>
<tr>
<td align="left">Signature <br>Lab-In-Charge</td>
<td align="center">Signature<br>Lab Assistant</td>
<td align="right">Signature <br>Head of Department</td>
</tr>
</table>
<br><br><br>
<input type="submit" value="SUBMIT" onclick='this.form.action="archive.php";myfun();'>
<input type="submit" value="SAVE AND CONTINUE LATER"
onclick='this.form.action="myphpformhandler.php";myfun();'>
</form>
<h3 align="center"><button onclick="myFunction()"><h3>Print this page</h3></button></h3>
</body>
</html>
i have created the JSFiddle but the multiplication is not working in it.
http://jsfiddle.net/xkY4Z/2/

Not a perfect solution to your problem but a bit closer Working Fiddle
Done using jQuery
$(document).on('change','input', function () {
var id = $(this).attr('id').split("-");
var answer = (Number($('#qty-' + id[1]).val()) * Number($('#price-' + id[1]).val())).toFixed(2);
$('#totalprice-' + id[1]).val(answer);
});
Update
Working Fiddle with name
Latest
Fiddle with Grand total

Struggling with DOM elements

I have an html table in my .aspx page which looks as follows:
<table id="quotationsListTable" class="quoteTbl" width="100%" border="1">
<tr>
<th></th>
<th>REF</th>
<th>Name</th>
<th>Arrival</th>
<th>Time</th>
<th>Departure</th>
<th>Time</th>
<th>Curr</th>
<th>Sale</th>
<th>Cost</th>
</tr>
<tr>
<td><input type="checkbox" name="chk"/></td>
<td> 1 </td>
<td><input type="text" style="width: 50px" /> </td>
<td><input type="text" style="width: 150px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
<td> <input type="text" style="width: 50px"/> </td>
</tr>
</table>
I also have a javascript function for deleting all the rows in my table, calling my by element ID "quotationsListTable".
The javascript function which stays in a separate .js file is a follows:
deleteAllrows('quotationsListTable');
function deleteAllrows(tableID) {
try {
var table = document.getElementByID(tableID);
var rowCount = table.rows.length;
for (var i = 1; i < rowCount; i++) {
var row = table.rows[i];
var chkbox = row.cells[0].childNodes[0];
table.deleteRow(i);
rowCount--;
i--;
}
} catch (e) {
alert(e);
}
}
The problem at hand is that my js function cannot retrieve the table by id, the error message that is thrown is 'undefined'.

It's document.getElementById note the small d
var table = document.getElementById(tableID);
https://developer.mozilla.org/en-US/docs/DOM/document.getElementById

I suggest that you include the jquery library and remove the rows with single line .. check this fiddle http://jsfiddle.net/SamirAdel/DyXHt/
deleteAllrows('quotationsListTable');
function deleteAllrows(tableID) {
$("#"+tableID+"tr:gt(0)").remove()
}

You should set your function after the page content is ready.
And please, change your "getElementByID" to "getElementById", D um lowercase.
Try to use jQuery, is an easy way.
See:
<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<script>
$().ready(function(){
deleteAllrows();
function deleteAllrows() {
try {
var table = document.getElementById('quotationsListTable');
alert(table);
var rowCount = table.rows.length;
for (var i = 1; i < rowCount; i++) {
var row = table.rows[i];
var chkbox = row.cells[0].childNodes[0];
table.deleteRow(i);
rowCount--;
i--;
}
} catch (e) {
alert(e);
}
}
});
</script>