<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>无标题页</title>
</head>
<script type="text/javascript">
function testClick()
{
document.getElementById("tsrc").src="a2.html"
}
</script>
<body>
<div style="display:none"><iframe id="tsrc"></iframe></div>
<input id="Button1" type="button" value="异步加载script" onclick="testClick()"/>
</body>
</html>