How can I programmatically scrape a web page and "click" a javascript button?

Question

I'm trying to scrape a web page for work where there are hundreds of table rows with a check box, and to submit the form I need to click a button which calls a javascript function. The button in html looks like this:

<a onclick="JavaScript: return verifyChecked('Resend the selected request for various approvals?');"
id="_ctl0_cphMain_lbtnReapprove"
title="Click a single request to send to relevant managers for reapproval."
class="lnkDBD" href="javascript:__doPostBack('_ctl0$cphMain$lbtnReapprove','')"
style="border-color:#0077D4;border-width:1px;border-style:Solid;text-decoration: overline;">&nbsp;Resend&nbsp;</a>

I know with libraries like beautiful soup you can submit forms by adding post data to the url, but how could I check a checkbox and "click" this javascript button? The website is a help desk of sorts, and for this particular button we can only check one request at a time which takes way too long when there are hundreds of requests that need re-submitted.

When I check the checkbox a message also pops up verifying that I want to do this, I don't know if that will affect programmatically submit it.

EDIT: I forgot to include the doPostBack method.

<script type="text/javascript"> 
<!--
var theForm = document.forms['aspnetForm'];
if (!theForm) {
    theForm = document.aspnetForm;
}
function __doPostBack(eventTarget, eventArgument) {
    if (!theForm.onsubmit || (theForm.onsubmit() != false)) {
        theForm.__EVENTTARGET.value = eventTarget;
        theForm.__EVENTARGUMENT.value = eventArgument;
        theForm.submit();
    }
}
// -->
</script>

Answer 1

Get Firefox and Firebug, open Firebug load up the page, and look in the console tab for what its actually sending to the server.

Then just repeat what its sending using what ever tool you like.