紧急求助 怎么在超连接打开的窗口中操作连接窗口的对象

给个例子你看看;a.html-------------------<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>a.html</title>
<script language="javascript">
function openwin()
{
var win=open("b.html");
}
</script>
</head><body>
<input type="button" name="Submit" value="按钮" onclick="openwin()"/>
<div id="div1">此处显示新 Div 标签的内容</div>
</body>
</html>
b.html---------------------<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>b.html</title>
<script language="javascript">
function exec()
{
opener.document.all.div1.style.display = 'none';
}
</script>
</head><body>
<input type="button" name="Submit" value="按钮" onclick="exec()"/>
</body>
</html>