<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
 <%
 String path = request.getContextPath();
 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 <html>
   <head>
     <base href="<%=basePath%>">
     
     <title>My JSP 'index.jsp' starting page</title>
  <meta http-equiv="pragma" content="no-cache">
  <meta http-equiv="cache-control" content="no-cache">
  <meta http-equiv="expires" content="0">    
  <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
  <meta http-equiv="description" content="This is my page">
  <!--
  <link rel="stylesheet" type="text/css" href="styles.css">
  -->
  <script type="text/javascript">
  window.οnlοad=function(){
  var oInput =document.getElementById('input1');
  var oIframe =document.getElementById('iframe1');
  oInput.οnclick=function(){
 alert(oIframe.contentWindow);/获取window对象
 //oIframe.contentWindow.document.getElementById('div1').style.color='red';ie都支持
  oIframe.contentDocument.getElementById('div1').style.background='red';//ie6,7不支持
  }
  }
  </script>
   </head>
   
   <body>
   <input  type="button"  value="改变" id="input1" />
   <iframe  src="left.jsp"  id="iframe1"></iframe>
   </body>
 </html>


//******************************************
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
 <%
 String path = request.getContextPath();
 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 <html>
   <head>
     <base href="<%=basePath%>">
     
     <title>My JSP 'left.jsp' starting page</title>
     
  <meta http-equiv="pragma" content="no-cache">
  <meta http-equiv="cache-control" content="no-cache">
  <meta http-equiv="expires" content="0">    
  <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
  <meta http-equiv="description" content="This is my page">
  <!--
  <link rel="stylesheet" type="text/css" href="styles.css">
  -->  </head>
   
   <body>
    <div  id="div1">aaa</div>
   </body>
 </html>