[转]javascript对联广告、漂浮广告封装类，多浏览器兼容

封装的JS方法：

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);
    }
}
var Class={
    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;
}
//对联广告类
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";
        }
    }
}
//漂浮广告类
var move_ad=Class.create();
move_ad.prototype={
    initialize:function(imgOption,initPosition,delay){
        this.imgOptions=Object.extend({url:"",link:"",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; "+this.imgOptions.width+"px;";
        vHtmlString+=" height:"+this.imgOptions.height+"px; z-index:10;'><a href='"+this.imgOptions.link+"' target='_blank'><img src='"+this.imgOptions.url+"' width="+this.imgOptions.width+" height="+this.imgOptions.height+" style='border:none;' /></a></div>";
        //vHtmlString+=" height:"+this.imgOptions.height+"px; z-index:10;'><img src='"+this.imgOptions.url+"' width="+this.imgOptions.width+" height="+this.imgOptions.height+" style='border:none;' /></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);    
    }
}

调用：

/* 
对联广告调用 
第一个参数为ID,第二个参数图片,第三个参数广告距离顶部的距离, 
第四个参数表示左右(true代表左,false代表右),第五个参数对联广告的宽度 
*/ 
new float_ad("ad_l","<img src='/System/uploads/allimg/090504/2346400.gif' />",50,true,64); 
new float_ad("ad_r","<img src='/System/uploads/allimg/090504/2346400.gif' />",50,false,64); 

/* 
漂浮广告调用 
第一个参数中的url代表漂浮广告的图片URL地址(必选项),link链接到页面网址,alt图片提示文字,width图片的宽度(可选项,默认120),heihgt图片的高度(可选项,默认120) 
第二个参数中的代表漂浮广告的初始位置,由参数left和top指定 
第三个参数代表浮动速度，0为静止，越小浮动速度越快 
*/ 
new move_ad({url:"/System/uploads/allimg/090504/2346400.gif",link:"http://www.yuanchuang.net",alt:"关于招募“2009中国·大连国际樱桃节”志愿者的通知",200,height:200},{left:40,top:160},20); 

参考：http://www.yuanchuang.net/content/21872.html