居中显示页面(任何分辨率下)

<script type="text/javascript" language="javascript">

    function ShowPage()

    {

        //打开页面的宽度

        var width='500';

        //打开页面的高度

        var height='400';

        //window.screen.width为当前屏幕宽度

        var left=(window.screen.width-width)/2;

        //window.screen.height为当前屏幕高度

        var top=(window.screen.height-height)/2;

        var str='width='+width+',height='+height+',top='+top+',left='+left;

        window.open(url,'',str);

    }

</script>