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How to allow only Credit/Debit card number format in ASP.NET textbox

I have to allow only Debit/Credit card number format in asp.net textbox. Below is a sample screenshot-
Please let me know how to do this with asp.net textbox and I don't have to use validators.
Note: I only have to allow numbers and after every 4 numbers there
should be a hyphen(-).

I would strongly recommend you not to reinvent the bicycle and use jQuery inputmask plugin which will let you do the following:
$("input").inputmask({
mask: "9999 9999 9999 9999",
placeholder: ""
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery.inputmask/3.3.4/jquery.inputmask.bundle.js"></script>
<input type="text"/>
Note that in this code I assumed that card number consists of 4 groups of 4 digits each, and it is not always true - it depends on expected cards' payment systems, country etc.
You can easily achieve any result by adding or removing digits in mask.

You can do the following:
<input type="text" onkeypress="return allowNumbersAndHyphen(event)">
function allowNumbersAndHyphen(evt) {
var charCode = (evt.which) ? evt.which : event.keyCode;
//allowing numbers, left key(37) right key(39) backspace(8) delete(46) and hyphen(45)
var length = $('input').val().length;
if (((charCode == 37 || charCode == 39 || charCode == 8 || charCode == 46 || charCode == 45) || !(charCode > 31 && (charCode < 48 || charCode > 57))) && length <19)
{
return true;
}
else{
return false;
}
}
//put hyphens atomatically
$(document).ready(function(){
$('input').on('keypress', function() {
var temp = $(this).val();
if (temp.length == 4 || temp.length == 9 || temp.length == 14) {
$('input').val(temp + '-');
}
});
$('input').on('blur', function() {
var regex = /^[0-9]{4}-[0-9]{4}-[0-9]{4}-[0-9]{4}$/;
var cardNumber = $(this).val();
if(regex.test(cardNumber)) {
//success
alert('successful');
}
else {
//show your error
alert('Error');
}
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- begin snippet: js hide: false console: true babel: false -->

Using vanilla javascript
document.getElementById('inp1').onkeypress = verify;
console.clear();
function isKeyValid(key) {
if(key > 47 && key < 58) return true
else if(key === 45) return true;
else return false;
}
function isValidCard(arr, isDash) {
const last = arr[arr.length - 1];
if(last.length === 4 && !isDash) return false;
else if(isDash && last.length !== 4) return false;
else if(isDash && arr.length === 4) return false;
else return true;
}
function verify(e) {
const key = e.keyCode || e.which;
const isDash = key === 45;
const val = e.target.value;
const input = val.split('-');
if (!isKeyValid(key) || !isValidCard(input, isDash)) {
return e.preventDefault();
}
// ...do something
}

Number validation along with decimals in key press event

I am doing validation of number except on case. I am doing validation in key press event.
This is the process how am doing my validation..
Output length = Integral + decimals
Example: Integral = 5, decimals = 3
If user enter five digits then am not allowing to enter 6th digit. (i.e. 12345).
But if he type '.' then after am allowing to 3 decimals (i.e. 12345.678). This is working perfectly.
Am facing the issue with below case.
If user enter 1.234 then he navigating to before '.' place using arrows or by mouse click, then user unable to enter another digit. Because I am checking either the integral part or decimal part match the length then I am returning false.
Can any one help me out this. I can do with key up event, but I am trying to achieve this by key press event only. Is there any way to get the position where user entering the digit, if yes then I can get one solution.
var integral = 5, decimals = 3;
//below code in the key press event
if ([8, 9, 13, 37, 39,46].indexOf(e.keyCode) != -1) {
return true;
} else if (e.keyCode == 190 && !e.shiftKey && decimals) {
_value = $(this).val();
if (_value.indexOf('.') != -1) {
return false;
}
return true;
} else if (48 >= e.keyCode || e.keyCode <= 57) {
_value = $(this).val();
if (decimals) {
_value = _value.split('.');
if (_value[0].length == integral || (_value[1] || '').length == decimals) {
return false;
}
return true;
} else {
if (_value.length == integral) {
return false;
}
return true;
}
}
return false;

I used selectionEnd for getting position of where user is typing the digit. Using that I did it.
var evt = e.target || e.srcElement;
_value = $(evt).val();
if ([8, 9, 13, 37, 39, 46].indexOf(e.keyCode) != -1) {
return true;
}
else if (e.keyCode == 190 && !e.shiftKey && decimals) {
if (_value.indexOf('.') != -1) {
return false;
}
return true;
}
else if (48 >= e.keyCode || e.keyCode <= 57) {
if (decimals) {
var isHavingDot = false;
var dotPosition = '';
if (_value.indexOf('.') != -1) {
isHavingDot = true;
dotPosition = _value.indexOf('.')
}
var length = _value.length;
if (isHavingDot) {
_value = _value.split('.');
if (evt.selectionEnd <= dotPosition) {
if (_value[0].length >= integral) {
return false;
}
}
else if ((_value[1] || '').length >= decimals) {
return false;
}
}
else {
if (_value.length >= integral) {
return false;
}
}
return true;
}
else {
if (_value.length == integral) {
return false;
}
return true;
}
}
return false;

If you already know how to do it with the keyup event, then you should be able to take that code and insert it into the keypress handler and implement it on the value that would be in the input if you pass the value through.
For example (I assume your validation works like in the example):
$("#myinput").keypress(function (e) {
//first figure out what the value would be if the keypress were passed through
var key=(e.which) ? e.which : e.keyCode;
var inputvalue=String.fromCharCode((96 <= key && key <= 105)? key-48 : key)
var caretPos = document.getElementById("myinput").selectionStart;
var currentvalue=$("#myinput").val();
var outputstring=currentvalue.substring(0, caretPos) + inputvalue + currentvalue.substring(caretPos);
//allow decimals through
if (outputstring===".") {
e.preventDefault();
$("#myinput").val("0.");
return false;
}
//cancel keypress if they string already has a decimal
if(key===46) return (outputstring.split(".").length - 1)>2;
//now perform the truncation and validation
e.preventDefault();
var outputvalue=parseFloat(outputstring);
var decpart=Math.trunc((outputvalue- parseInt(outputvalue)) * 1000)/1000;
var intpart=Math.floor(outputvalue);
//perform your test on the output value here - only need to test the integer part, since the decimal part is truncated
var outputtest=String(intpart).length<=5;
if (outputtest){
//insert the value if it looks okay
$("#myinput").val(intpart+decpart);
}
return false;
});

best way to restrict special characters in text field input [duplicate]

How do I block special characters from being typed into an input field with jquery?

A simple example using a regular expression which you could change to allow/disallow whatever you like.
$('input').on('keypress', function (event) {
var regex = new RegExp("^[a-zA-Z0-9]+$");
var key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
if (!regex.test(key)) {
event.preventDefault();
return false;
}
});

I was looking for an answer that restricted input to only alphanumeric characters, but still allowed for the use of control characters (e.g., backspace, delete, tab) and copy+paste. None of the provided answers that I tried satisfied all of these requirements, so I came up with the following using the input event.
$('input').on('input', function() {
$(this).val($(this).val().replace(/[^a-z0-9]/gi, ''));
});
Edit:
As rinogo pointed out in the comments, the above code snippet forces the cursor to the end of the input when typing in the middle of the input text. I believe the code snippet below solves this problem.
$('input').on('input', function() {
var c = this.selectionStart,
r = /[^a-z0-9]/gi,
v = $(this).val();
if(r.test(v)) {
$(this).val(v.replace(r, ''));
c--;
}
this.setSelectionRange(c, c);
});

Short answer: prevent the 'keypress' event:
$("input").keypress(function(e){
var charCode = !e.charCode ? e.which : e.charCode;
if(/* Test for special character */ )
e.preventDefault();
})
Long answer: Use a plugin like jquery.alphanum
There are several things to consider when picking a solution:
Pasted text
Control characters like backspace or F5 may be prevented by the above code.
é, í, ä etc
Arabic or Chinese...
Cross Browser compatibility
I think this area is complex enough to warrant using a 3rd party plugin. I tried out several of the available plugins but found some problems with each of them so I went ahead and wrote jquery.alphanum. The code looks like this:
$("input").alphanum();
Or for more fine-grained control, add some settings:
$("#username").alphanum({
allow : "€$£",
disallow : "xyz",
allowUpper : false
});
Hope it helps.

Use simple onkeypress event inline.
<input type="text" name="count" onkeypress="return /[0-9a-zA-Z]/i.test(event.key)">

Use HTML5's pattern input attribute!
<input type="text" pattern="^[a-zA-Z0-9]+$" />

Use regex to allow/disallow anything. Also, for a slightly more robust version than the accepted answer, allowing characters that don't have a key value associated with them (backspace, tab, arrow keys, delete, etc.) can be done by first passing through the keypress event and check the key based on keycode instead of value.
$('#input').bind('keydown', function (event) {
switch (event.keyCode) {
case 8: // Backspace
case 9: // Tab
case 13: // Enter
case 37: // Left
case 38: // Up
case 39: // Right
case 40: // Down
break;
default:
var regex = new RegExp("^[a-zA-Z0-9.,/ $#()]+$");
var key = event.key;
if (!regex.test(key)) {
event.preventDefault();
return false;
}
break;
}
});

Your textbox:
<input type="text" id="name">
Your javascript:
$("#name").keypress(function(event) {
var character = String.fromCharCode(event.keyCode);
return isValid(character);
});
function isValid(str) {
return !/[~`!##$%\^&*()+=\-\[\]\\';,/{}|\\":<>\?]/g.test(str);
}

Take a look at the jQuery alphanumeric plugin. https://github.com/KevinSheedy/jquery.alphanum
//All of these are from their demo page
//only numbers and alpha characters
$('.sample1').alphanumeric();
//only numeric
$('.sample4').numeric();
//only numeric and the .
$('.sample5').numeric({allow:"."});
//all alphanumeric except the . 1 and a
$('.sample6').alphanumeric({ichars:'.1a'});

this is an example that prevent the user from typing the character "a"
$(function() {
$('input:text').keydown(function(e) {
if(e.keyCode==65)
return false;
});
});
key codes refrence here:
http://www.expandinghead.net/keycode.html

I use this code modifying others that I saw. Only grand to the user write if the key pressed or pasted text pass the pattern test (match) (this example is a text input that only allows 8 digits)
$("input").on("keypress paste", function(e){
var c = this.selectionStart, v = $(this).val();
if (e.type == "keypress")
var key = String.fromCharCode(!e.charCode ? e.which : e.charCode)
else
var key = e.originalEvent.clipboardData.getData('Text')
var val = v.substr(0, c) + key + v.substr(c, v.length)
if (!val.match(/\d{0,8}/) || val.match(/\d{0,8}/).toString() != val) {
e.preventDefault()
return false
}
})

$(function(){
$('input').keyup(function(){
var input_val = $(this).val();
var inputRGEX = /^[a-zA-Z0-9]*$/;
var inputResult = inputRGEX.test(input_val);
if(!(inputResult))
{
this.value = this.value.replace(/[^a-z0-9\s]/gi, '');
}
});
});

Write some javascript code on onkeypress event of textbox.
as per requirement allow and restrict character in your textbox
function isNumberKeyWithStar(evt) {
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57) && charCode != 42)
return false;
return true;
}
function isNumberKey(evt) {
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57))
return false;
return true;
}
function isNumberKeyForAmount(evt) {
var charCode = (evt.which) ? evt.which : event.keyCode
if (charCode > 31 && (charCode < 48 || charCode > 57) && charCode != 46)
return false;
return true;
}

To replace special characters, space and convert to lower case
$(document).ready(function (){
$(document).on("keyup", "#Id", function () {
$("#Id").val($("#Id").val().replace(/[^a-z0-9\s]/gi, '').replace(/[_\s]/g, '').toLowerCase());
});
});

Yes you can do by using jQuery as:
<script>
$(document).ready(function()
{
$("#username").blur(function()
{
//remove all the class add the messagebox classes and start fading
$("#msgbox").removeClass().addClass('messagebox').text('Checking...').fadeIn("slow");
//check the username exists or not from ajax
$.post("user_availability.php",{ user_name:$(this).val() } ,function(data)
{
if(data=='empty') // if username is empty
{
$("#msgbox").fadeTo(200,0.1,function() //start fading the messagebox
{
//add message and change the class of the box and start fading
$(this).html('Empty user id is not allowed').addClass('messageboxerror').fadeTo(900,1);
});
}
else if(data=='invalid') // if special characters used in username
{
$("#msgbox").fadeTo(200,0.1,function() //start fading the messagebox
{
//add message and change the class of the box and start fading
$(this).html('Sorry, only letters (a-z), numbers (0-9), and periods (.) are allowed.').addClass('messageboxerror').fadeTo(900,1);
});
}
else if(data=='no') // if username not avaiable
{
$("#msgbox").fadeTo(200,0.1,function() //start fading the messagebox
{
//add message and change the class of the box and start fading
$(this).html('User id already exists').addClass('messageboxerror').fadeTo(900,1);
});
}
else
{
$("#msgbox").fadeTo(200,0.1,function() //start fading the messagebox
{
//add message and change the class of the box and start fading
$(this).html('User id available to register').addClass('messageboxok').fadeTo(900,1);
});
}
});
});
});
</script>
<input type="text" id="username" name="username"/><span id="msgbox" style="display:none"></span>
and script for your user_availability.php will be:
<?php
include'includes/config.php';
//value got from the get method
$user_name = trim($_POST['user_name']);
if($user_name == ''){
echo "empty";
}elseif(preg_match('/[\'^£$%&*()}{##~?><>,|=_+¬-]/', $user_name)){
echo "invalid";
}else{
$select = mysql_query("SELECT user_id FROM staff");
$i=0;
//this varible contains the array of existing users
while($fetch = mysql_fetch_array($select)){
$existing_users[$i] = $fetch['user_id'];
$i++;
}
//checking weather user exists or not in $existing_users array
if (in_array($user_name, $existing_users))
{
//user name is not availble
echo "no";
}
else
{
//user name is available
echo "yes";
}
}
?>
I tried to add for / and \ but not succeeded.
You can also do it by using javascript & code will be:
<!-- Check special characters in username start -->
<script language="javascript" type="text/javascript">
function check(e) {
var keynum
var keychar
var numcheck
// For Internet Explorer
if (window.event) {
keynum = e.keyCode;
}
// For Netscape/Firefox/Opera
else if (e.which) {
keynum = e.which;
}
keychar = String.fromCharCode(keynum);
//List of special characters you want to restrict
if (keychar == "'" || keychar == "`" || keychar =="!" || keychar =="#" || keychar =="#" || keychar =="$" || keychar =="%" || keychar =="^" || keychar =="&" || keychar =="*" || keychar =="(" || keychar ==")" || keychar =="-" || keychar =="_" || keychar =="+" || keychar =="=" || keychar =="/" || keychar =="~" || keychar =="<" || keychar ==">" || keychar =="," || keychar ==";" || keychar ==":" || keychar =="|" || keychar =="?" || keychar =="{" || keychar =="}" || keychar =="[" || keychar =="]" || keychar =="¬" || keychar =="£" || keychar =='"' || keychar =="\\") {
return false;
} else {
return true;
}
}
</script>
<!-- Check special characters in username end -->
<!-- in your form -->
User id : <input type="text" id="txtname" name="txtname" onkeypress="return check(event)"/>

just the numbers:
$('input.time').keydown(function(e) { if(e.keyCode>=48 &&
e.keyCode<=57) {
return true; } else {
return false; } });
or for time including ":"
$('input.time').keydown(function(e) { if(e.keyCode>=48 &&
e.keyCode<=58) {
return true; } else {
return false; } });
also including delete and backspace:
$('input.time').keydown(function(e) { if((e.keyCode>=46 &&
e.keyCode<=58) || e.keyCode==8) { return true; } else {
return false; } });
unfortuneatly not getting it to work on a iMAC

Wanted to comment on Alex's comment to Dale's answer. Not possible (first need how much "rep"? That wont happen very soon.. strange system.)
So as an answer:
Backspace can be added by adding \b to the regex definition like this: [a-zA-Z0-9\b].
Or you simply allow the whole Latin range, including more or less anything "non exotic" characters (also control chars like backspace): ^[\u0000-\u024F\u20AC]+$
Only real unicode char outside latin there is the euro sign (20ac), add whatever you may need else.
To also handle input entered via copy&paste, simply also bind to the "change" event and check the input there too - deleting it or striping it / giving an error message like "not supported characters"..
if (!regex.test($j(this).val())) {
alert('your input contained not supported characters');
$j(this).val('');
return false;
}

Restrict specials characters on keypress. Here's a test page for key codes: http://www.asquare.net/javascript/tests/KeyCode.html
var specialChars = [62,33,36,64,35,37,94,38,42,40,41];
some_element.bind("keypress", function(event) {
// prevent if in array
if($.inArray(event.which,specialChars) != -1) {
event.preventDefault();
}
});
In Angular, I needed a proper currency format in my textfield. My solution:
var angularApp = angular.module('Application', []);
...
// new angular directive
angularApp.directive('onlyNum', function() {
return function( scope, element, attrs) {
var specialChars = [62,33,36,64,35,37,94,38,42,40,41];
// prevent these special characters
element.bind("keypress", function(event) {
if($.inArray(event.which,specialChars) != -1) {
prevent( scope, event, attrs)
}
});
var allowableKeys = [8,9,37,39,46,48,49,50,51,52,53,54,55,56
,57,96,97,98,99,100,101,102,103,104,105,110,190];
element.bind("keydown", function(event) {
if($.inArray(event.which,allowableKeys) == -1) {
prevent( scope, event, attrs)
}
});
};
})
// scope.$apply makes angular aware of your changes
function prevent( scope, event, attrs) {
scope.$apply(function(){
scope.$eval(attrs.onlyNum);
event.preventDefault();
});
event.preventDefault();
}
In the html add the directive
<input only-num type="text" maxlength="10" id="amount" placeholder="$XXXX.XX"
autocomplete="off" ng-model="vm.amount" ng-change="vm.updateRequest()">
and in the corresponding angular controller I only allow there to be only 1 period, convert text to number and add number rounding on 'blur'
...
this.updateRequest = function() {
amount = $scope.amount;
if (amount != undefined) {
document.getElementById('spcf').onkeypress = function (e) {
// only allow one period in currency
if (e.keyCode === 46 && this.value.split('.').length === 2) {
return false;
}
}
// Remove "." When Last Character and round the number on blur
$("#amount").on("blur", function() {
if (this.value.charAt(this.value.length-1) == ".") {
this.value.replace(".","");
$("#amount").val(this.value);
}
var num = parseFloat(this.value);
// check for 'NaN' if its safe continue
if (!isNaN(num)) {
var num = (Math.round(parseFloat(this.value) * 100) / 100).toFixed(2);
$("#amount").val(num);
}
});
this.data.amountRequested = Math.round(parseFloat(amount) * 100) / 100;
}
...

You don't need jQuery for this action
You can achieve this using plain JavaScript, You can put this in the onKeyUp event.
Restrict - Special Characters
e.target.value = e.target.value.replace(/[^\w]|_/g, '').toLowerCase()
Accept - Number only
e.target.value = e.target.value.replace(/[^0-9]/g, '').toLowerCase()
Accept - Small Alphabet only
e.target.value = e.target.value.replace(/[^0-9]/g, '').toLowerCase()
I could write for some more scenarios but I have to maintain the specific answer.
Note It will work with jquery, react, angular, and so on.

$(this).val($(this).val().replace(/[^0-9\.]/g,''));
if( $(this).val().indexOf('.') == 0){
$(this).val("");
}
//this is the simplest way
indexof is used to validate if the input started with "."

[User below code to restrict special character also
$(h.txtAmount).keydown(function (event) {
if (event.shiftKey) {
event.preventDefault();
}
if (event.keyCode == 46 || event.keyCode == 8) {
}
else {
if (event.keyCode < 95) {
if (event.keyCode < 48 || event.keyCode > 57) {
event.preventDefault();
}
}
else {
if (event.keyCode < 96 || event.keyCode > 105) {
event.preventDefault();
}
}
}
});]

Allow only numbers in TextBox (Restrict Alphabets and Special Characters)
/*code: 48-57 Numbers
8 - Backspace,
35 - home key, 36 - End key
37-40: Arrow keys, 46 - Delete key*/
function restrictAlphabets(e){
var x=e.which||e.keycode;
if((x>=48 && x<=57) || x==8 ||
(x>=35 && x<=40)|| x==46)
return true;
else
return false;
}

/**
* Forbids special characters and decimals
* Allows numbers only
* */
const numbersOnly = (evt) => {
let charCode = (evt.which) ? evt.which : evt.keyCode;
if (charCode === 46 && charCode > 31 && (charCode < 48 || charCode > 57)) {
return false;
}
let inputResult = /^[0-9]*$/.test(evt.target.value);
if (!inputResult) {
evt.target.value = evt.target.value.replace(/[^a-z0-9\s]/gi, '');
}
return true;
}

In HTML:
<input type="text" (keypress)="omitSpecialChar($event)"/>
In JS:
omitSpecialChar(event) {
const keyPressed = String.fromCharCode(event.keyCode);
const verifyKeyPressed = /^[a-zA-Z\' \u00C0-\u00FF]*$/.test(keyPressed);
return verifyKeyPressed === true;
}
In this example it is possible to type accents.

$(document).ready(function() {
$('#Description').bind('input', function() {
var c = this.selectionStart,
r = /[^a-z0-9 .]/gi,
v = $(this).val();
if (r.test(v)) {
$(this).val(v.replace(r, ''));
c--;
}
this.setSelectionRange(c, c);
if (!(checkEmpty($("#Description").val()))) {
$("#Description").val("");
} //1Apr2022 code end
});
$('#Description').on('change', function() {
if (!(checkEmpty($("#Description").val()))) {
$("#Description").val("");
} //1Apr2022 code end
});
});
function checkEmpty(field) { //1Apr2022 new code
if (field == "" ||
field == null ||
field == "undefinied") {
return false;
} else if (/^\s*$/.test(field)) {
return false;
} else {
return true;
}
}

A more enhanced form would be
$('input[type=text]').on('input', function() {
var c = this.selectionStart,
r = /[^a-z ]/gi,
v = $(this).val();
if(r.test(v)) {
$(this).val(v.replace(r, ''));
c--;
}
this.setSelectionRange(c, c);
});
Because it will allow you to enter space as well and it will only target the input fields with type text and wont bother the other input fields like email, password etc as normally we need special characters in email and password field

javascript validation for allow -1 and all positive numbers in text box

I am trying to validate a text box to allow all positive numbers including -1 in it.
i tried this, which will work for allowing only positive numbers
function allownumbers(e, txtBox) {
var key;
key = (e.keyCode) ? e.keyCode : e.charCode;
if (e.charCode == 0) {
return true;
}
if ((key < 48 || key > 57) && (key != 46) && (key != 44)) {
return false;
}
if (key == 46) {
if ((txtBox.value).indexOf('.') != -1) {
return false;
}
}
if (key == 44) {
if ((txtBox.value).indexOf(',') != -1) {
return false;
}
}
return true;
}
But how to allow -1(only) with all positive numbers
Thanks in advance

Instead of preventing keystrokes, why not validate and sanitize the input? Maybe something like this:
function allownumbers(e, txtBox) {
var val = parseInt(txtBox.value);
if(!val || val < -1) {
val = 0; // invalid value, reset to zero
}
txtBox.value = val;
}

phone number validation with added input

I recently filled out a form and when I got to the phone number textBox I noticed some really cool things going on. As I entered my number, general phone symbols were getting added automatically. Example:
I start entering my area code '555'
and my input was changed to 1 (555)
to test what just happened I backspaced on the ) and it quickly added it back in.
So my question is, how do I get this input to happen?

I use a javascript library called automask - you dont see the mask but it wont let you type anything outside the mask
for instance if your mask is ###-###-#### then any other characters are ignored (ie not 0-9) and the dashes are put in automatically.
I can post the library if you would like to take a look at
example of implementation
<input type=text name=ssn onkeypress="return autoMask(this,event, '###-##-####');">
// email kireol at yahoo.com
// autoMask - an adaption of anyMask
//
// this will force #'s, not allowing alphas where the #'s are, and auto add -'s
function autoMask(field, event, sMask) {
//var sMask = "**?##?####";
var KeyTyped = String.fromCharCode(getKeyCode(event));
var targ = getTarget(event);
keyCount = targ.value.length;
if (getKeyCode(event) < 32)
{
return true;
}
if(keyCount == sMask.length && getKeyCode(event) > 32)
{
return false;
}
if ((sMask.charAt(keyCount+1) != '#') && (sMask.charAt(keyCount+1) != 'A' ) && (sMask.charAt(keyCount+1) != '~' ))
{
field.value = field.value + KeyTyped + sMask.charAt(keyCount+1);
return false;
}
if (sMask.charAt(keyCount) == '*')
return true;
if (sMask.charAt(keyCount) == KeyTyped)
{
return true;
}
if ((sMask.charAt(keyCount) == '~') && isNumeric_plusdash(KeyTyped))
return true;
if ((sMask.charAt(keyCount) == '#') && isNumeric(KeyTyped))
return true;
if ((sMask.charAt(keyCount) == 'A') && isAlpha(KeyTyped))
return true;
if ((sMask.charAt(keyCount+1) == '?') )
{
field.value = field.value + KeyTyped + sMask.charAt(keyCount+1);
return true;
}
return false;
}
function getTarget(e) {
// IE5
if (e.srcElement) {
return e.srcElement;
}
if (e.target) {
return e.target;
}
}
function getKeyCode(e) {
//IE5
if (e.srcElement) {
return e.keyCode
}
// NC5
if (e.target) {
return e.which
}
}
function isNumeric(c)
{
var sNumbers = "01234567890";
if (sNumbers.indexOf(c) == -1)
return false;
else
return true;
}
function isNumeric_plusdash(c)
{
var sNumbers = "01234567890-";
if (sNumbers.indexOf(c) == -1)
return false;
else
return true;
}
function isAlpha(c)
{
var lCode = c.charCodeAt(0);
if (lCode >= 65 && lCode <= 122 )
{
return true;
}
else
return false;
}
function isPunct(c)
{
var lCode = c.charCodeAt(0);
if (lCode >= 32 && lCode <= 47 )
{
return true;
}
else
return false;
}

If this was an aspx page, they were probably using the AJAX Control Toolkit MaskedEdit Extender. There is also the Masked Input plugin for jQuery.