How do I handle __doPostBack() in Greasemonkey?

Question

There are a series of links handled by that function that contain what I need and I'm trying to use Greasemonkey to save the content inside those links.

Here's what I've tried:

var content;
var viewstate;
var crystalstate;

$(document).ready(function() {

viewstate = $("#__VIEWSTATE").val();
crystalstate = $("#__CRYSTALSTATEctl00$main$CrystalReportViewer1").val();

$.post("CautarePolite.aspx", { 
__EVENTTARGET: 'ctl00$main$gvPolite$ctl02$lbDetaliiPolita', 
__EVENTARGUMENT: '', 
__CRYSTALSTATEctl00$main$CrystalReportViewer1: crystalstate,
__VIEWSTATE: viewstate
}, 
function( data ) {
      content = data;
  } );

alert('');

$.post("script_url.php", { data: content } );

});

This gives me a page with the following error message:

"Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster."

Here is a bit of the code on the page which may be of interest:

<form method="post" action="CautarePolite.aspx" id="aspnetForm" class="wrap">
<div class="aspNetHidden">
<input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />
<input type="hidden" name="__EVENTARGUMENT" id="__EVENTARGUMENT" value="" />
<input type="hidden" name="__CRYSTALSTATEctl00$main$CrystalReportViewer1" id="long value*" />
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="*very long value*" />
</div>

<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>

Answer 1

It was missing __VIEWSTATEENCRYPTED

The input field was further down in the source code, but that solved it. I got what I needed.