漂浮广告（从上往下飘最后消失）

   <script type="text/javascript"> 
        
            var adtime = 100;   //时间
            var adheight =0;    //高度
            
            $(document).ready(function(){
                addCount(); 
                adtime=300;
                setTimeout("noneAds()",7000); //停留时间
            })
 
            function addCount() 
            { 
                if(adtime>0) { 
                    adtime--; 
                    adheight = adheight+5; 
                }else { 
                    return; 
                } 
                if(adheight>415)  //高度 
                { 
                    return; 
                } 
                document.getElementById("ad01").style.display = ""; 
                document.getElementById("ad01").style.height = adheight+"px"; 
                setTimeout("addCount()",30); 
            } 
            var N = 415; //高度 
            function noneAds() { 
                if(adtime>0){ 
                    adtime--; 
                    N = N-5; 
                }else { 
                    return; 
                } 
                if(N<0){ 
                    document.getElementById("ad01").style.display = "none"; 
                    return; 
                } 
                document.getElementById("ad01").style.height = N+"px"; 
                setTimeout("noneAds()",30); 
            } 
        </script>