iframe引用长度自适应

1.加入js方法

 <script language="javascript">
          function SetCwinHeight()
	{
		var iframe = document.getElementById("courseware");
		try{
			var bHeight = iframe.contentWindow.document.body.scrollHeight;
			var dHeight = iframe.contentWindow.document.documentElement.scrollHeight;
			var height = Math.max(bHeight, dHeight);
			/** 浏览器判断 */
			var Sys = {};
        var ua = navigator.userAgent.toLowerCase();
        var s;
        (s = ua.match(/msie ([\d.]+)/)) ? Sys.ie = s[1] :
        (s = ua.match(/firefox\/([\d.]+)/)) ? Sys.firefox = s[1] :
        (s = ua.match(/chrome\/([\d.]+)/)) ? Sys.chrome = s[1] :
        (s = ua.match(/opera.([\d.]+)/)) ? Sys.opera = s[1] :
        (s = ua.match(/version\/([\d.]+).*safari/)) ? Sys.safari = s[1] : 0;

        //以下进行测试
        if (Sys.ie) iframe.height =  bHeight;
        if (Sys.firefox) iframe.height =  height;
        if (Sys.chrome) iframe.height =  height;
        if (Sys.opera) iframe.height =  height;
        if (Sys.safari) iframe.height =  height;
			
		}catch (ex){}
	}
	</script>

2.引入iframe

<iframe onload="Javascript:SetCwinHeight()" allowtransparency="true" frameborder="0" scrolling="no" id="courseware" marginheight="0" marginwidth="0" width="100%" height="100%"  name="courseware" src="http://www.jiankangbaobei.net"></iframe>

3.问题
大家常说的跨域访问我没有测试，但ie，ff，chrome等都没问题，ff下长度变长后缩不会去，不知道大家发现没有