以下这段要怎么才能延时显示呢?例如3秒后才显示
<script>
var a="http://hao123.com"
</script>
<iframe id="cs" src="about:blank" width = "500" height="500"> </iframe>
<SCRIPT LANGUAGE="JavaScript">
<!--
document.getElementById("cs").src=a;
//-->
</SCRIPT>
<script>
var a="http://hao123.com"
</script>
<iframe id="cs" src="about:blank" width = "500" height="500"> </iframe>
<SCRIPT LANGUAGE="JavaScript">
<!--
document.getElementById("cs").src=a;
//-->
</SCRIPT>
<SCRIPT LANGUAGE="JavaScript">
<!--
var a="http://hao123.com"
setTimeout(function(){document.getElementById("cs").src=a},3000)
//-->
</SCRIPT>