/**
 *
 * @access public
 * @return void
 **/
function ImageZoom(name,width,height){
	this.name       = name;
	this.maxWidth   = width;
	this.maxHeight  = height;

	this.images;
	this.preImage   = new Image();
	this.speed      = Array();
	this.needZoom   = Array();
	this.origWidth  = Array();
	this.origHeight = Array();

	this.init=function(){
		this.images=this.getElementsByClassName('zoom','img');
		var parent;
		var img,i;

		for(i in this.images){
			if(this.images[i].tagName!="IMG") continue;
			this.origWidth[i]=this.images[i].offsetWidth;
			this.origHeight[i]=this.images[i].offsetHeight;

			this.preImage.src=this.images[i].src;

			var ratio =this.preImage.height/this.preImage.width;
			var ratioX=this.preImage.width/this.origWidth[i];
			var ratioY=this.preImage.height/this.origHeight[i];

			var maxsize=(this.origWidth[i]>this.origHeight[i])?this.origWidth[i]:this.origHeight[i];

			imgname='imgZoom'+i;
			if(this.isIE())	img=document.createElement('<img src="'+this.images[i].src+'" id="'+imgname+'" onmouseover="'+this.name+'.start('+i+');" onmouseout="'+this.name+'.cancel('+i+');" border="0">');
			else {
				img=document.createElement('img');
				img.setAttribute('src',this.images[i].src);
				img.setAttribute('id',imgname);
				img.setAttribute('onmouseover',this.name+'.start('+i+')');
				img.setAttribute('onmouseout',this.name+'.cancel('+i+')');
			}
			img.style.border="none";
			img.style.zIndex="50";
			img.style.position="relative";

			if(ratioX>=ratioY){
				img.style.width=this.origWidth[i]+"px";
				img.style.height=(this.preImage.height/ratioX)+"px";
			} else {
				img.style.width=(this.preImage.width/ratioY)+"px";
				img.style.height=this.origHeight[i]+"px";
			}

			parent=this.images[i].parentNode;
			parent.replaceChild(img,this.images[i]);

			this.needZoom[i]=false;
			this.origWidth[i]=img.offsetWidth;
			this.origHeight[i]=img.offsetHeight;
		}
	}

	this.zoom=function(imgID){
		var img=document.getElementById('imgZoom'+imgID);
		var diffX=(this.maxWidth-img.offsetWidth)/5;
		var diffY=(this.maxHeight-img.offsetHeight)/5;
		var imgRatio=(this.origWidth[imgID]/this.origHeight[imgID]);

		if(imgRatio<1){
			this.speed[imgID]=(diffY>2)?diffY:2;
			if(img.offsetHeight<this.maxHeight){
				img.style.width=(img.offsetWidth+this.speed[imgID]*imgRatio)+"px";
				img.style.height=(img.offsetHeight+this.speed[imgID])+"px";
			} else this.needZoom[imgID]=false;
		} else {
			this.speed[imgID]=(diffX>2)?diffX:2;
			if(img.offsetWidth<this.maxWidth){
				img.style.width=(img.offsetWidth+this.speed[imgID])+"px";
				img.style.height=(img.offsetHeight+this.speed[imgID]/imgRatio)+"px";
			} else this.needZoom[imgID]=false;
		}
		if(this.needZoom[imgID]) setTimeout(this.name+'.zoom(\''+imgID+'\');',50);
	}

	this.zoomOut=function(imgID){
		if(this.needZoom[imgID]) return true;

		var img=document.getElementById('imgZoom'+imgID);
		var diffX=(img.offsetWidth-this.origWidth[imgID])/5;
		var diffY=(img.offsetHeight-this.origHeight[imgID])/5;
		var imgRatio=(this.origWidth[imgID]/this.origHeight[imgID]);

		if(imgRatio<1){
			this.speed[imgID]=(diffY>2)?diffY:2;
			if(img.offsetHeight>this.origHeight[imgID]){
				img.style.width=(img.offsetWidth-this.speed[imgID]*imgRatio)+"px";
				img.style.height=(img.offsetHeight-this.speed[imgID])+"px";
				setTimeout(this.name+'.zoomOut('+imgID+');',50);
			} else {
				img.style.width=this.origWidth[imgID]+'px';
				img.style.height=this.origHeight[imgID]+'px';
			}
		} else {
			this.speed[imgID]=(diffX>2)?diffX:2;
			if(img.offsetWidth>this.origWidth[imgID]){
				img.style.width=(img.offsetWidth-this.speed[imgID])+"px";
				img.style.height=(img.offsetHeight-this.speed[imgID]/imgRatio)+"px";
				setTimeout(this.name+'.zoomOut('+imgID+');',50);
			} else {
				img.style.width=this.origWidth[imgID]+'px';
				img.style.height=this.origHeight[imgID]+'px';
			}
		}
	}

	this.start=function(imgID){
		var img=document.getElementById('imgZoom'+imgID);
		if(!this.needZoom[imgID]){
			this.needZoom[imgID]=true;
			if(img.offsetWidth<this.maxWidth) setTimeout(this.name+'.zoom('+imgID+');',50);
		}
	}

	this.cancel=function(imgID){
		var img=document.getElementById('imgZoom'+imgID);
		this.needZoom[imgID]=false;
		if(img.offsetWidth>=this.origWidth[imgID]) setTimeout(this.name+'.zoomOut('+imgID+');',50);
	}

	this.getElementsByClassName=function(className, tag, elm){
		var testClass = new RegExp("(^|\\s)" + className + "(\\s|$)");
		var tag = tag || "*";
		var elm = elm || document;
		var elements = (tag == "*" && elm.all)? elm.all : elm.getElementsByTagName(tag);
		var returnElements = [];
		var current;
		var length = elements.length;
		for(var i=0; i<length; i++){
			current = elements[i];
			if(testClass.test(current.className)){
				returnElements.push(current);
			}
		}
		return returnElements;
	}

	this.isIE=function(){
		return /msie/i.test(navigator.userAgent) && !/opera/i.test(navigator.userAgent);
	}

	this.addInit(this.name);
}