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How to call a Greasemonkey function when a JavaScript link is clicked

So I recently started working on Greasemonkey scripts without much prior experience in JavaScript. It was going fine until I hit this roadbloack.
I'm writing a script for a page that has a small table of information. If a link at the bottom is clicked, the table expands fully in the page to display all information. I need to call a function in Greasemonkey when this happens, however, the link doesn't appear to have an ID or anything I can actually reference to watch it. It's simply this:
When it's clicked, the table expands and it then shows as true. I initially used the following to expand the table upon loading the page, but that broke several things:
window.location.href = ('javascript: expandFullTable(false)');
I've attempted using "click", "onclick", and even "mouseover" to have Greasemonkey detect when it's pressed but nothing seems to work. From what I can tell it's simply a link that calls a function, but after some significant searching I wasn't able to find out anything about how to reference it in my script. I'm sure it's incredibly simple, but it's frustrated me to no end.

You can hijack the function like this:
var oldExpandFullTable = unsafeWindow.expandFullTable;
unsafeWindow.expandFullTable = function() {
// Do something
alert("You clicked on that thing!");
// Call the original function
oldExpandFullTable.apply(this, arguments);
};
But since you tagged this jquery this should let you retrieve the link:
var link = $("a[href^=\"javascript: expandFullTable\"]);
It should work if jQuery is injected into your script with #require. If it's already in the page, you can add this before to access it: var $ = unsafeWindow.jQuery;.
And by the way, perhaps you should learn more about unsafeWindow to avoid security holes.

Completely delete all instances of a div with a specific class using javascript/jquery?

I am using Popup.js by Toddish.
http://docs.toddish.co.uk/popup/demos/
Long story short, the popup plugin creates divs by default given the classes ".popup_back" and ".popup_cont".
I have another button I wish to press which should completely delete the added divs with those classes after they have been generated and added to the html. As if they never even existed. Surely this is possible?
I have tried running a function which simply runs:
$(".popup_back").remove();
$(".popup_cont").remove();
As shown in this example:
http://www.w3schools.com/jquery/tryit.asp?filename=tryjquery_dom_remove
Unfortunately despite the code running, the actual divs are never deleted as required.
Any ideas? I am new to this kind of thing and have googled around and read a lot about DOM etc but am yet to crack it.
Thanks
EDIT:
In reply to the comments:
The Javascript:
function removePopups() { // This function is called to remove the popups.
console.log("removing...");
$(".popup_back").remove();
$(".popup_cont").remove();
}
function func(url) { // url is the url of the image to be displayed within the popup.
removePopups(); // As soon as the function casillas is called, removePopups is used to remove any existing instances of the divs.
$('a.theimage').popup({ // This is where the Popup plugin is utilised.
content : $(url),
type : 'html'
});
}
The HTML:
<a class="theimage" onclick="func('image/image1.jpg')" href="#" >
Long story short, an image is displayed in the popup.
I think the issue is that the popup plugin runs due to the class but the function func is never actually run when the click occurs. However simultaneously "removing..." still prints out in the console which tells me that the function IS being executed. The problem is I want the popup plugin to run together with the javascript function. Is there a solution for this conflict?

Your implementation should really be as simple as this:
<a class="theimage" href="#" >Open</a>
Bind the popup creation to your popup link:
$('a.theimage').popup({
content : 'image/image1.jpg',
type : 'html'
});
I'm speculating here, but what might be happening is that you're invoking the popup twice by binding the popup() call to a click handler in your markup. The popup plugin already binds the popup creation to a click event.
View working demo. Note the 3 external resource: the popup CSS, the popup JS, and the jQuery JS.

Html onmousedown vs href Precedence

I use the following code in one of my html pages.
When user clicks "Search Engines" links it opens yahoo.com on a new page and Google on current page.
I've tested this and it works (opens both urls), but is there any chance that the page will complete the window.location (redirect to a different page) without completing the href command?
Is there a rule for Precedence between the two command?
**Note: I know I can solve the problem in different ways, but I'm curious about this specific situation.
<html>
<head>
<title></title>
<script type="text/javascript">
function clickRedirect() {
window.location = 'http://www.google.com';
}
</script>
<body>
<a onmousedown="clickRedirect()" href="http://www.yahoo.com" target="_blank">Search Engines</a>
</body>
</html>

The mousedown event will happen first, but as you can see from the fact your code is currently working, that's not the whole story.
The question is: Once the mousedown has happened and you've set window.location, does the page get whisked away immediately (and therefore processing of the default action of the click on the a element doesn't happen), or does that default action get completed before the page is destroyed and replaced with the new page?
The answer is: I don't think that's guaranteed behavior at all (either way), and I wouldn't rely on it cross-browser. For one thing, what if the user holds down the mouse button? Since the default action of an a element isn't triggered until a click, which requires a mouseup.
Instead, I'd probably hedge my bets, in two ways:
First, I'd use click, not mousedown, for this. Users don't expect pages to swap out when they just hold the mouse down.
Second, I'd change your function:
function clickRedirect() {
setTimeout(function() {
window.location = "http://www.google.com";
}, 0);
}
Now you're specifically giving the browser a chance to complete the default action of the click before you go off to another page.
You might find more information on this buried deep in the DOM events specifications:
DOM2 Events
DOM3 Events
...in that they might say something about what should happen when an event is in progress and the page is being destroyed. I didn't immediately see anything.

How do I discover which function is called when I press a button?

I'm stuck modifying someone else's source code, and unfortunately it's very strongly NOT documented.
I'm trying to figure out which function is called when I press a button as part of an effort to trace the current bug to it's source, and I"m having no luck. From what I can tell, the function is dynamically added to the button after it's generated. As a result, there's no onlick="" for me to examine, and I can't find anything else in my debug panel that helps.
While I prefer Chrome, I'm more than willing to boot up in a different browser if I have to.

In Chrome, type the following in your URL bar after the page has been fully loaded (don't forget to change the button class):
var b = document.getElementsByClassName("ButtonClass"); alert(b[0].onclick);
or you can try (make the appropriate changes for the correct button id):
var b = document.getElementById("ButtonID"); alert(b.onclick);
This should alert the function name/code snippet in a message box.
After having the function name or the code snippet you just gotta perform a seach through the .js files for the snippet/function name.
Hope it helps!

Open page with your browser's JavaScript debugger open
Click "Break all" or equivalent
Click button you wish to investigate (may require some finesse if mouseovering page elements causes events to be fired. If timeouts or intervals occur in the page, they may get in the way, too.)

Inspect the buttons markup and look at its class / id. Use that class or id and search the JavaScript, it's quite likely that the previous developer has done something like
document.getElementById('someId').onclick = someFunction...;
or
document.getElementById('someId').addEventListener("click", doSomething, false);

You can add a trace variable to each function. Use console.log() to view the trace results.
Like so:
function blah(trace) {
console.log('blah called from: '+trace);
}
(to view the results, you have to open the developer console)

triggering a jQuery function n seconds after the tab/window is in view

I am using jQuery to have a promotional window opening up -say- 5 seconds after a page is loaded. But the effect is lost for people who open the page in a new window or a new tab. When they get to my tab the window will already be open.
Is there a way to get this to fire when people actually start viewing my site?
I was thinking about catching a scroll or something, but people don't get started scrolling immediately and most won't scroll at all. Other than that I am out of ideas.
I am not sure if jQuery offers a solution here... javascript?
Thanks.

the following should do the trick .. (jQuery)
<script type="text/javascript">
function initiatePopup(){
$(window).unbind('blur');
$(window).unbind('focus');
// do the popup
};
$(document).ready(
function(){
$(window).focus( initiatePopup ).blur( initiatePopup );
// your other functions should go from here on
}
);
</script>
[EDIT] on OP request..
code edited to make the example all inclusive
[EDIT 2]
The code above has been edited again because we need to handle the blur event as well.. so we take the code for the popup somewhere else in order to not duplicate it inside both events..
[EDIT 3]
if you want to pass parameters to the popup if they are created later on, then change the event binding line to
$(window).focus( function() { initiatePopup(params); } ).blur( function() { initiatePopup(params); );
and of course change the initiatePopup to accept parameters ..

Would putting a div around everything work with an onmouseover event listener? I've never tried it, so I'm not sure whether that would fire or not, but it might be worth a shot.