Missing $_POST element.

When form is re-submitted via JavaScript on another page, one (and maybe more, I haven't looked) of the $_POST values is missing.  Many others do exist.

A text box with the same name/id as the requested $_POST element exists on the submitted form (I've verified the name/id.) and that text box contains text, but PHP is throwing an "Undefined index:" error when I do a "$v = $_POST['xx']".  I did a dump of the $_POST elements and it is not there.

If, however, I re-submit from the form itself (not from another open page), that $_POST value DOES exist.

As a note, there are over 100 fields on the re-submitted page.  Don' t know if this would affect it, or not.

Has anyone heard of this behavior and, if so, how to correct?

Thanks,
Bruce

JavaScript that submits page. It is on the active window, function is called by a button click:

function CloseIt()
{
	if (!(window.opener.document.adiApproveOrder == undefined) 
	 && !(window.opener.document.adiApproveOrder.closed)) {
		var actn = document.getElementById("action").value;
		if (actn == "approved") {
			window.opener.document.adiApproveOrder['action'].value = "deliver";
		} else if (actn == "submitted") {
			window.opener.document.adiApproveOrder['action'].value = "submitted";
		} else {
			window.opener.document.adiApproveOrder['action'].value = "";
		}
		window.opener.document.adiApproveOrder.submit();
	}
	window.close();
}