JavaScript couplet ads, floating ad packaging (IE, FF, Opera, Safari, Chrome)

Code:

program code
/*
The first parameter of the couplet advertisement call is the ID, the second parameter is the picture, and the third parameter is the distance between the advertisement and the top.
The fourth parameter represents left and right (true represents left, false represents right), and the fifth parameter represents the width of the couplet advertisement.
*/
new float_ad("ad_l","<img src='/u/info_img/2009-06/11/2009Cherry.gif' />",50,true,64);
new float_ad("ad_r","<img src='/u/info_img/2009-06/11/2009Cherry.gif' />",50,false,64);

/*
The url in the first parameter of the floating ad call represents the image URL address of the floating ad (required), the link to the page URL, the alt image prompt text, the width of the image (optional, default 120), and the height of the heihgt image ( Optional, default 120)
The second parameter represents the initial position of the floating advertisement, which is specified by the parameters left and top. The third parameter represents the floating speed. 0 is static. The smaller the value, the faster the floating speed.
*/
new move_ad({url:" /u/info_img/2009-06/11/2009Cherry.gif",link:"http://jzyouth.org.cn/html/zixun/zuixingonggao/2009327/zxgg47926848.html",alt : "Notice on recruiting volunteers for the "2009 China Dalian International Cherry Festival", width: 200, height: 200}, {left: 40, top: 160}, 20);

// core code
function $(element){
if(arguments.length>1){
for(var i=0,elements=[],length=arguments.length;i<length;i++)
elements.push($(arguments[i]));
return elements;
}
if(typeof element=="string")
return document.getElementById(element);
else
return element;
}
Function.prototype.bind=function(object){
var method=this;
return function(){
method.apply(object,arguments);
}
}
varClass={
create:function(){
return function(){
this.initialize.apply(this,arguments);
}
}
}
Object.extend=function(destination,resource){
for(var property in resource){
destination[property]=resource[property];
}
return destination;
}
//Couplet advertising http://www.knowsky.com/article.asp?typeid=36
var float_ad=Class.create();
float_ad.prototype={
initialize:function(id,content,top,left,width){
document.write('<div id='+id+' style="position:absolute;">'+content+'</div>');
this.id=$(id);
this.top=top;
if(!!left){
this.id.style.left="8px";
}else{
this.id.style.left=(document.documentElement.clientWidth-width-8)+"px";
window.onresize=function(){
this.id.style.left=(document.documentElement.clientWidth-width-8)+"px";
}.bind(this);
}
this.id.style.top=top+"px";

this.interId=setInterval(this.scroll.bind(this),20);
},
scroll:function(){
this.stmnStartPoint = parseInt(this.id.style.top, 10);
this.stmnEndPoint =document.documentElement.scrollTop+ this.top;
if(navigator.userAgent.indexOf("Chrome")>0){
this.stmnEndPoint=document.body.scrollTop+this.top;
}
if ( this.stmnStartPoint != this.stmnEndPoint ) {
this.stmnScrollAmount = Math.ceil( Math.abs( this.stmnEndPoint - this.stmnStartPoint ) / 15 );
this.id.style.top = parseInt(this.id.style.top, 10) + ( ( this.stmnEndPoint<this.stmnStartPoint ) ? -this.stmnScrollAmount : this.stmnScrollAmount )+"px";
}
}
}
//Floating advertising class
var move_ad=Class.create();
move_ad.prototype={
initialize:function(imgOption,initPosition,delay){
this.imgOptions=Object.extend({url:"",link:"",alt:"",width:120,height:120},imgOption||{});
this.adPosition=Object.extend({left:40,top:120},initPosition||{});
this.delay =delay;
this.step = 1;
this.herizonFlag=true;
this.verticleFlag=true;
this.id="ad_move_sg";
var vHtmlString="<div id='"+this.id+"' style='position:absolute; left:"+this.adPosition.left+"px; top:"+this.adPosition.top+"px; width:" +this.imgOptions.width+"px;";
vHtmlString+=" height:"+this.imgOptions.height+"px; z-index:10;'><a href='"+this.imgOptions.link+"' target='_blank' title='"+this.imgOptions .alt+"'><img src='"+this.imgOptions.url+"' width='"+this.imgOptions.width+"' height='"+this.imgOptions.height+"' style='border:none; ' alt='"+this.imgOptions.alt+"' /></a></div>";
document.write(vHtmlString);
this.id=$(this.id);
this.intervalId=setInterval(this.scroll.bind(this),this.delay);
this.id.onmouseover=this.stop.bind(this);
this.id.onmouseout=this.start.bind(this);
},
scroll:function(){
var L=T=0;
var B=document.documentElement.clientHeight-this.id.offsetHeight;
var R=document.documentElement.clientWidth-this.id.offsetWidth;
this.id.style.left=this.adPosition.left+document.documentElement.scrollLeft+"px";
this.id.style.top=this.adPosition.top+document.documentElement.scrollTop+"px";
this.adPosition.left =this.adPosition.left + this.step*(this.herizonFlag?1:-1);
if (this.adPosition.left < L) { this.herizonFlag = true; this.adPosition.left = L;}
if (this.adPosition.left > R){ this.herizonFlag = false; this.adPosition.left = R;}
this.adPosition.top =this.adPosition.top + this.step*(this.verticleFlag?1:-1);
if(this.adPosition.top <= T){ this.verticleFlag=true; this.adPosition.top=T;}
if(this.adPosition.top >= B){ this.verticleFlag=false; this.adPosition.top=B; }
},
stop:function(){
clearInterval(this.intervalId);
},
start:function(){
this.intervalId=setInterval(this.scroll.bind(this),this.delay);
}
}