原生js 写漂浮广告栏

//js部分

<script> 

var Rimifon = { 
"Ads" : new Object, 
"NewFloatAd" : function(imgUrl, strLink) 
{ 
var ad = document.createElement("a"); 
ad.DirV = true; 
ad.DirH = true; 
ad.AutoMove = true; 
ad.Image = new Image; 
ad.Seed = Math.random(); 
ad.Timer = setInterval("Rimifon.Float(" + ad.Seed + ")", 50); 
this.Ads[ad.Seed] = ad; 
ad.Image.Parent = ad; 
ad.style.position = "absolute"; 
ad.style.left = 0; 
ad.style.top = 0; 
ad.Image.src = imgUrl; 
ad.Image.onmouseover = function(){this.Parent.AutoMove = false;} 
ad.Image.onmouseout = function(){this.Parent.AutoMove = true;} 
if(strLink) 
{ 
ad.href = strLink; 
ad.Image.border = 0; 
ad.target = "_blank"; 
} 
ad.appendChild(ad.Image); 
document.body.appendChild(ad); 
return ad; 
}, 
"Float" : function(floatId) 
{ 
var ad = this.Ads[floatId]; 
if(ad.AutoMove) 
{ 
var curLeft = parseInt(ad.style.left); 
var curTop = parseInt(ad.style.top); 
if(ad.offsetWidth + curLeft > document.body.clientWidth + document.body.scrollLeft - 1) 
{ 
curLeft = document.body.scrollLeft + document.body.clientWidth - ad.offsetWidth; 
ad.DirH = false; 
} 
if(ad.offsetHeight + curTop > document.body.clientHeight + document.body.scrollTop - 1) 
{ 
curTop = document.body.scrollTop + document.body.clientHeight - ad.offsetHeight; 
ad.DirV = false; 
} 
if(curLeft < document.body.scrollLeft) 
{ 
curLeft = document.body.scrollLeft; 
ad.DirH = true; 
} 
if(curTop < document.body.scrollTop) 
{ 
curTop = document.body.scrollTop; 
ad.DirV = true; 
} 
ad.style.left = curLeft + (ad.DirH ? 10 : -1) + "px"; 
ad.style.top = curTop + (ad.DirV ? 10 : -1) + "px"; 
} 
} 
} 
</script>

<script> 

//自定义内容

var ad = Rimifon.NewFloatAd("xxx"); 
ad.style.left = 500; 
ad.style.top = 456; 
ad.Image.width = 88; 
ad.Image.height = 31; 
</script>