I'm trying to access the data at http://www.bogc.dnrc.mt.gov/WebApps/...ltiSearch.aspx

If I search a county like "richland" it returns results. Then I can click pages. Every link on their site uses a function to navigate. The script is below:

HTML Code:
<script type="text/javascript">
//<![CDATA[
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>
The function is accessed like so: (

HTML Code:
<a href="javascript:__doPostBack('ctl00$SiteContentPlaceHolder$DataGrid1$ctl01$ctl06','')">7</a>

All it it appears to do is change the values of the below inputs, and submit the form.
HTML Code:
<input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />
<input type="hidden" name="__EVENTARGUMENT" id="__EVENTARGUMENT" value="" />
It also has a hidden input called __VIEWSTATE which appears to be some type of session ID which has to be changed to send the POST. No big deal.

The real question is, when I input the values into the hidden inputs themselves (EVENTTARGET AND EVENTARGUMENT), and post the form to their site, it doesn't return anything. But if I use the function to post, it works! Ideas?