求高手js的有关问题_J2SE

求高手js的问题
这段代码用来实现图片在页面上下左右飘动的，，在IE里可以四处飘动，但火狐和360就只是靠在上面左右移动

HTML code

<script type="text/javascript">            //js漂浮窗口                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 = 15;             ad.Timer = setInterval("Rimifon.Float(" + ad.Seed + ")", 30);             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 ? 1 : -1) + "px";             ad.style.top = curTop + (ad.DirV ? 1 : -1) + "px";             }             }             }</script>

------解决方案--------------------
从这里开始
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;
}