lunzi

<form action="x.action" method="post">
<input type="hidden" name="from" id="from" value="" />
<input type="image" src="images/flash.jpg" />
</form>
<script language="javascript">
	var url = window.location.search;
	var i = url.indexOf("from=");
	var j = url.indexOf("&",i+5);	
	var from="";
	if(i>=0){
		from = j>i?url.substring(i+5,j):url.substring(i+5);
	}
	document.getElementById("from").value= from;
</script>