求方法！

[sun0903]

先判断是否if6, 如果是则调用a.js.否则调用b.js. 在下初学，还请大家不吝赐教！

[浴火_凤凰]

楼主是要IE6吧，找出一个IE6的特有方法或者Bug就可以了

[Jeremiah_Java]

     <script type="text/javascript">
        var Sys = {};
        var ua = navigator.userAgent.toLowerCase();
        if (window.ActiveXObject)
            Sys.ie = ua.match(/msie ([\d.]+)/)[1]
        else if (document.getBoxObjectFor)
            Sys.firefox = ua.match(/firefox\/([\d.]+)/)[1]
        else if (window.MessageEvent && !document.getBoxObjectFor)
            Sys.chrome = ua.match(/chrome\/([\d.]+)/)[1]
        else if (window.opera)
            Sys.opera = ua.match(/opera.([\d.]+)/)[1]
        else if (window.openDatabase)
            Sys.safari = ua.match(/version\/([\d.]+)/)[1];
        
        //以下进行测试
        if(Sys.ie) document.write('IE: '+Sys.ie);
        if(Sys.firefox) document.write('Firefox: '+Sys.firefox);
        if(Sys.chrome) document.write('Chrome: '+Sys.chrome);
        if(Sys.opera) document.write('Opera: '+Sys.opera);
        if(Sys.safari) document.write('Safari: '+Sys.safari);

    </script>

能判断无数的浏览器.

[s_liangchao1s]

<script type="text/javascript">
<!--
	if(true){
		document.write("<script src='a.js'>" + "</" + "script>");
	}else{
		document.write("<script src='b.js'>" + "</" + "script>");
	}
//-->
</script>