以下操作写在body里面，form表单外

<iframe id="agentFrame" name="agentFrame" src="" width="0" height="0" style="display:none;" ></iframe> 
<script type="text/javascript"> 
function sethash(){ 
hashH = document.documentElement.scrollHeight; //获取自身高度 
urlC = "/test.jsp"; //设置iframeA的src 
document.getElementById("agentFrame").src=urlC+"#"+hashH; //将高度作为参数传递 
} 
window.onload=sethash; 
</script>

test.jsp如下：

<%@ page contentType="text/html;charset=GBK" language="java"%> 
<script> 
function pseth() { 
var iObj = parent.parent.document.getElementById('infoFrame'); 
iObjH = parent.parent.frames["infoFrame"].frames["agentFrame"].location.hash; 
iObj.style.height = iObjH.split("#")[1]+"px"; 
} 
window.onload=pseth(); 
</script>