Default.aspx
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<iframe src="HTMLPage1.htm" width="500px" height="200px"></iframe>
<iframe src="HTMLPage2.htm" width="500px" height="500px"></iframe>
</div>
</form>
</body>
</html>
===============================================
HTMLPage1.htm
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function frameSetNum()
{
var text=window.parent.frames[1].document.getElementById("Text1");
text.value=parseInt(text.value,10)+1;
}
</script>
</head>
<body>
<input id="Button1" type="button" value="修改文本值" onclick="frameSetNum()" />
</body>
</html>
===============================================
HTMLPage2.htm
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
</head>
<body>
<input id="Text1" type="text" value="0" />
</body>
</html>
===============================================
效果为:每点击一次“修改文本值”按钮。文本框里的数值加一。
不知道是不是你要的。