浏览器<=IE6提示更换浏览器

var BrowserUpgrade = function(){
    var IsbrowserUpgrade = 0;    
    if(IsbrowserUpgrade!=1){
        browserUpgrade = '<div class="lteie6_transparent"></div>';
        browserUpgrade +='<div class="lteie6_main">';
        browserUpgrade +=    '<h2 class="lteie6_title" title="反Internet Explorer 6"><span>反Internet Explorer 6</span></h2>';
        browserUpgrade +=    '<p class="lteie6_cont">为推动浏览器的W3C标准及更好的用户体验，本站建议你使用Internet Explorer 6 以上版本的浏览器。或安装/使用下列新版本浏览器，在此感激你为推动互联网作出贡献。</p>';
        browserUpgrade +=    '<ul class="lteie6_browser">';
        browserUpgrade +=        '<li><a class="ie8" title="下载Internet Explorer 8" href="http://www.microsoft.com/windows/internet-explorer/beta/worldwide-sites.aspx">Internet Explorer 8</a></li>';
        browserUpgrade +=        '<li><a class="firefox" target="_blank" title="下载Firefox" href="http://www.mozillaonline.com/">Firefox</a></li>';
        browserUpgrade +=        '<li><a class="chrome" target="_blank" title="下载Chrome" href="http://www.google.com/chrome/">Chrome</a></li>';
        browserUpgrade +=        '<li><a class="opera" target="_blank" title="下载Opera" href="http://cn.opera.com/download/thanks/win/">Opera</a></li>';
        browserUpgrade +=        '<li><a class="safari" target="_blank" title="下载Safari" href="http://www.apple.com.cn/safari/download/">Safari</a></li>';
        browserUpgrade +=    '</ul>';
        browserUpgrade +=    '<p class="more"><a class="link" title="详细活动信息" href="http://www.webrebuild.org/">活动详细<strong class="support"><span class="em">web</span><span class="strong">rebuild.</span><span class="important">org</span></strong></a></p>';
        browserUpgrade +=    '<p class="close"></p>';
        browserUpgrade +='</div>';
        browserUpgrade +='<style type="text/css">';
        browserUpgrade +='body{height:100%;}';
        browserUpgrade +='.lteie6_transparent{position:absolute;top:0;left:0;width:100%;height:100%;background:#000000;filter:alpha(opacity=20);opacity: 0.2;}';
        browserUpgrade +='.lteie6_main *{margin:0;padding:0;border:none; font-family:Verdana,"宋体";}';
        browserUpgrade +='.lteie6_main .lteie6_title,';
        browserUpgrade +='.lteie6_main .ie8,';
        browserUpgrade +='.lteie6_main .firefox,';
        browserUpgrade +='.lteie6_main .chrome,';
        browserUpgrade +='.lteie6_main .opera,';
        browserUpgrade +='.lteie6_main .safari,';
        browserUpgrade +='.lteie6_main .close{padding-left:19px;background:url(http://www.webrebuild.org/browser_upgrade/img/lte_ie6.png) no-repeat;}';
        browserUpgrade +='.lteie6_main .close span,';
        browserUpgrade +='.lteie6_main .lteie6_title span{display:none}';
        browserUpgrade +='.lteie6_main{position:absolute;top:50%;left:50%;margin:-80px 0 0 -250px;border:4px solid #1D6120;width:500px;height:185px;background:#FFFFFF;}';
        browserUpgrade +='.lteie6_main .lteie6_title{float:left;display:inline;margin:20px;padding:0;width:155px;height:86px;}';
        browserUpgrade +='.lteie6_main .lteie6_cont{float:left;margin-top:20px;width:290px;font:12px/180% Verdana!important;text-align:left;color:#5B5B5B;}';
        browserUpgrade +='.lteie6_main .lteie6_browser{position:absolute;top:135px;left:0;}';
        browserUpgrade +='.lteie6_main .lteie6_browser li{display:inline;padding-left:18px;}';
        browserUpgrade +='.lteie6_main .lteie6_browser a{display:inline-block;text-decoration:underline;height:18px;font:12px/18px Verdana;color:#5B5B5B;}';
        browserUpgrade +='.lteie6_main .lteie6_browser a:hover{color:#1D6120;}';
        browserUpgrade +='.lteie6_main .ie8{background-position:-156px 0;}';
        browserUpgrade +='.lteie6_main .firefox{background-position:-156px -18px;}';
        browserUpgrade +='.lteie6_main .chrome{background-position:-156px -36px;}';
        browserUpgrade +='.lteie6_main .opera{background-position:-156px -54px;}';
        browserUpgrade +='.lteie6_main .safari{background-position:-156px -72px;}';
        browserUpgrade +='.lteie6_main .close{position:absolute;top:4px;right:4px;padding:0;overflow:hidden;border:none;line-height:50px;width:14px;height:14px;font-size:0;cursor:pointer;background-position:-158px -93px;}';
        browserUpgrade +='.lteie6_main .close button{width:14px;height:14px;background:1px solid #f00;cursor:pointer;}';
        browserUpgrade +='.lteie6_main .more{position:absolute;top:162px;right:6px; font-size:11px;font-family:Verdana}';
        browserUpgrade +='.lteie6_main .more .link{color:#5B5B5B;}';
        browserUpgrade +='.lteie6_main .more .support span{font-weight:bold;}';
        browserUpgrade +='.lteie6_main .more .em{color:#9FE222;}';
        browserUpgrade +='.lteie6_main .more .strong{color:#1D6120;}';
        browserUpgrade +='.lteie6_main .more .important{color:#5B5B5B;}';
        browserUpgrade +='</style>';
        var browserUpgradeContainer = document.createElement("div");
        browserUpgradeContainer.id='browserUpgrade';
        browserUpgradeContainer.className='lte_ie6';
        browserUpgradeContainer.innerHTML=browserUpgrade;
        var browserUpgradeCloser = document.createElement("button");
        browserUpgradeCloser.onclick=function(){document.getElementById('browserUpgrade').style.display='none';}
        browserUpgradeCloser.innerHTML='关闭';
        browserUpgradeContainer.getElementsByTagName('p')[2].appendChild(browserUpgradeCloser);
        document.body.appendChild(browserUpgradeContainer);
    }

}
window.attachEvent('onload',BrowserUpgrade);