String.prototype.format = function(){
		 var tmpStr = this;
		 var iLen = arguments.length;
		 for(var i=0;i<iLen;i++){
		  tmpStr = tmpStr.replace(new RegExp("\\{" + i + "\\}", "g"), arguments[i]);
		 }
		 return tmpStr;
		}

		function $() {
		  var elements = new Array();
		  for (var i = 0; i < arguments.length; i++) {
			var element = arguments[i];
			if (typeof element == 'string')
			  element = document.getElementById(element);

			if (arguments.length == 1) 
			  return element;

			elements.push(element);
		  }
		  return elements;
		}

		function IMarquee(){
		 function throwError(){alert("接口未实现：" + arguments[0]);}
		 this.Scroll = function(){throwError("Scroll");}
		 this.Clone = function(){throwError("Clone");}
		}

		function AbstractMarquee(){
		 IMarquee.apply(this);
		 var ref = this;
		 var timer = null;
		 var container = null;
		 var indexs = ["ContainerID", "Delay", "Amount", "Width", "Height"];
		 this.Amount = 1;
		 this.Delay = 60;
		 this.Width = 0;
		 this.Height = 0;
		 this.ContainerID = "";
		 this.Start = function(){
		  clearTimer();
		  timer = setInterval(ref.Scroll, ref.Delay);
		 }
		 this.Stop = function(){
		  clearTimer();
		 }
		 this.Pause = function(){
		  clearTimer();
		 }
		 this.Init = function(){
		  container = $(this.ContainerID);
		  if(container == null) {alert("无法找到id为{0}的对象,初始化失败。".format(this.ContainerID));return;};
		  container.style.overflow = "hidden";
		  if(this.Width > 0) container.style.width = this.Width + "px";
		  if(this.Height > 0) container.style.height = this.Height + "px";
		  this.Clone();
		  this.AttachEvent();
		  this.Start();
		 }
		 this.AttachEvent = function(){
		  container.onmouseover = ref.Pause;
		  container.onmouseout = ref.Start;
		 }

		 function clearTimer(){
		  if(timer != null)clearInterval(timer);
		 }

		 function _Marquee(){
		  var max = Math.min(indexs.length, arguments.length);
		  for(var i=0;i<max;i++)
		   this[indexs[i]] = arguments[i];
		 }

		 _Marquee.apply(this, arguments);
		}


		function MarqueeUp(){
		 AbstractMarquee.apply(this, arguments);
		 var ref = this;
		 var container = $(this.ContainerID);
		 this.Clone = function(){
		  container.innerHTML = '<div>{0}</div><div>{0}</div>'.format(container.innerHTML);
		 }
		 this.Scroll = function(){
		  with(container){
		   if(scrollTop >= lastChild.offsetTop) scrollTop -= firstChild.offsetHeight;
		   else scrollTop += ref.Amount;
		  }
		 }
		}


		function MarqueeDown(){
		 AbstractMarquee.apply(this, arguments);
		 var ref = this;
		 var container = $(this.ContainerID);
		 this.Clone = function(){
		  container.innerHTML = '<div>{0}</div><div>{0}</div>'.format(container.innerHTML);
		  container.scrollTop = container.scrollHeight;
		 }
		 this.Scroll = function(){
		  with(container){
		   if(scrollTop <= firstChild.offsetTop) scrollTop += lastChild.offsetHeight;
		   else scrollTop -= ref.Amount;
		  }
		 }
		}


		function MarqueeLeft(){
		 AbstractMarquee.apply(this, arguments);
		 var ref = this;
		 var container = $(this.ContainerID);
		 this.Clone = function(){
		  container.innerHTML = '<table cellspacing="0" cellpadding="0" border="0"><tr><td>{0}</td><td>{0}</td></tr></table>'.format(container.innerHTML);
		 }
		 this.Scroll = function(){
		  with(container){
		   if(scrollLeft >= firstChild.rows[0].cells[1].offsetLeft) scrollLeft -= firstChild.rows[0].cells[0].offsetWidth;
		   else scrollLeft += ref.Amount;
		  }
		 }
		}


		function MarqueeRight(){
		 AbstractMarquee.apply(this, arguments);
		 var ref = this;
		 var container = $(this.ContainerID);
		 this.Clone = function(){
		  container.innerHTML = '<table cellspacing="0" cellpadding="0" border="0"><tr><td>{0}</td><td>{0}</td></tr></table>'.format(container.innerHTML);
		  container.scrollLeft = container.scrollWidth;
		 }
		 this.Scroll = function(){
		  with(container){
		   if(scrollLeft <= firstChild.rows[0].cells[0].offsetLeft) scrollLeft += firstChild.rows[0].cells[1].offsetWidth;
		   else scrollLeft -= ref.Amount;
		  }
		 }
		}


		var Marquee = {
		 Type : {
		  UP : function(){return new MarqueeUp(arguments[0]);},
		  DOWN : function(){return new MarqueeDown(arguments[0]);},

		  LEFT : function(){return new MarqueeLeft(arguments[0]);},
		  RIGHT : function(){return new MarqueeRight(arguments[0]);}
		 },
		 newInstance : function(type, container){
		  return this.Type[type.toUpperCase()].call(this, container);
		 }
		}
		var marquee = Marquee.newInstance("Up", "demo");
		marquee.Init();