CSDN 的Google广告相关代码，如何关闭广告，拖网速

<div><script type="text/javascript" src="http://www.****.net/ui/scripts/Csdn/counter.js"></script></div> 
<div id="ad_left" style="position:absolute;width:120px;top:184px;left:10px;display:none;"> 
<a style="float:right;" href="#" onclick="javascript:this.parentNode.style.display='none';return false;">[关闭]</a> 
<script type="text/javascript"> 
    try {
        var pdate = "" + parent.eval("tinfo.pdate");
        if (pdate) {
            pdate = new Date(pdate.replace(/-/g, "/"));
            var today = new Date();
            showad = (today.getTime() - pdate.getTime()) / 1000 / 60 / 60 / 24 > 30;
        }
    } catch (ex) { };
showad=true;
    try {
        var ad_left = "";
        if (showad && screen.availWidth >= 1280) {
            ad_left += '<' + 'script type=\"text/javascript\">';
            ad_left += 'google_ad_client = "pub-1076724771190722";';
            ad_left += 'google_ad_slot =\"5633584852\";';
            ad_left += 'google_ad_width = 120;';
            ad_left += 'google_ad_height = 600;';
            ad_left += '</' + 'script>';
            ad_left += '<' + 'script type=\"text/javascript\"';
            ad_left += 'src=\"http://pagead2.googlesyndication.com/pagead/show_ads.js\">';
            ad_left += '</' + 'script>';
        }
        document.write(ad_left);
        document.getElementById("ad_left").style.display = "";
    } catch (e) { }
</script>