html代码：
<!DOCTYPE html>
<html>
<script>
function display()
{
var div=document.getElementById("my");
if(div.innerHTML!="")
{
div.innerHTML="";
return;
}
var xmlHttp=new XMLHttpRequest();
xmlHttp.open("GET","introduce.jsp",true);
xmlHttp.onreadystatechange=function()
{
if(xmlHttp.readyState==4 && xmlHttp.status == 200)
{div.innnerHTML=xmlHttp.responseText;
}
}xmlHttp.send();
}
</script>
<body>
<div id="my" style="background-color:yellow;widht:300px;height:400px"></div>
<input type="button" onclick="display()" value="hehe">
</body>
</html>
jsp代码：
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<html>
<body>
out.print("this is a demo");
</body>
</html>
原文：http://www.cnblogs.com/webglcn/p/3527411.html