function ScrollText(content,btnPrevious,btnNext,autoStart,timeout,isSmoothScroll)
	{
	    this.Speed = 10;
	    this.Timeout = timeout;
	 	  this.stopscroll =false;//是否停止滚动的标志位
	 	  this.isSmoothScroll= isSmoothScroll;//是否平滑连续滚动
	    this.LineHeight = 20;//默认高度。可以在外部根据需要设置
	    this.NextButton = this.$(btnNext);
	    this.PreviousButton = this.$(btnPrevious);
	    this.ScrollContent = this.$(content);
	    //this.ScrollContent.innerHTML += this.ScrollContent.innerHTML;//为了平滑滚动再加一遍
	
			if(this.PreviousButton)
			{
				this.PreviousButton.onclick = this.GetFunction(this,"Previous"); 
				this.PreviousButton.onmouseover = this.GetFunction(this,"MouseOver");
				this.PreviousButton.onmouseout = this.GetFunction(this,"MouseOut");
			}
			if(this.NextButton){
				this.NextButton.onclick = this.GetFunction(this,"Next");
				this.NextButton.onmouseover = this.GetFunction(this,"MouseOver");
				this.NextButton.onmouseout = this.GetFunction(this,"MouseOut");
		  }
	    this.ScrollContent.onmouseover = this.GetFunction(this,"MouseOver");
	    this.ScrollContent.onmouseout = this.GetFunction(this,"MouseOut");
	
	    if(autoStart)
	    {
	        this.Start();
	    }
	}
	
	ScrollText.prototype = {
		$:function(element)
		{
			return document.getElementById(element);
		},
		Previous:function()
		{
			this.stopscroll = true;
			this.Scroll("up");
		},
		Next:function()
		{
			this.stopscroll = true;
			this.Scroll("down");
		},
		Start:function()
		{
			if(this.isSmoothScroll)
			{
				this.AutoScrollTimer = setInterval(this.GetFunction(this,"SmoothScroll"), this.Timeout);
			}
			else
			{		
				this.AutoScrollTimer = setInterval(this.GetFunction(this,"AutoScroll"), this.Timeout);
			}
		},
		Stop:function()
		{
			clearTimeout(this.AutoScrollTimer);
			this.DelayTimerStop = 0;
		},
		MouseOver:function()
		{	
			this.stopscroll = true;
		},
		MouseOut:function()
		{
			this.stopscroll = false;
		},
		AutoScroll:function()
		{
			if(this.stopscroll) 
			{
				return;
			}
			this.ScrollContent.scrollTop++;
			if(parseInt(this.ScrollContent.scrollTop) % this.LineHeight != 0)
			{
				this.ScrollTimer = setTimeout(this.GetFunction(this,"AutoScroll"), this.Speed);
			}
			else
			{
				if(parseInt(this.ScrollContent.scrollTop) >= parseInt(this.ScrollContent.scrollHeight) / 2)
				{
					this.ScrollContent.scrollTop = 0;
				}
				clearTimeout(this.ScrollTimer);
				//this.AutoScrollTimer = setTimeout(this.GetFunction(this,"AutoScroll"), this.Timeout);
			}
		},
		SmoothScroll:function()
		{
			if(this.stopscroll) 
			{
				return;
			}
			this.ScrollContent.scrollTop++;
			if(parseInt(this.ScrollContent.scrollTop) >= parseInt(this.ScrollContent.scrollHeight) / 2)
			{
				this.ScrollContent.scrollTop = 0;
			}
		},
		Scroll:function(direction)
		{
			if(direction=="up")
			{
				this.ScrollContent.scrollTop--;
			}
			else
			{
				this.ScrollContent.scrollTop++;
			}
			if(parseInt(this.ScrollContent.scrollTop) >= parseInt(this.ScrollContent.scrollHeight) / 2)
			{
				this.ScrollContent.scrollTop = 0;
			}
			else if(parseInt(this.ScrollContent.scrollTop)<=0)
			{
				this.ScrollContent.scrollTop = parseInt(this.ScrollContent.scrollHeight) / 2;
			}
			
			if(parseInt(this.ScrollContent.scrollTop) % this.LineHeight != 0)
			{
				this.ScrollTimer = setTimeout(this.GetFunction(this,"Scroll",direction), this.Speed);
			}
		},
		GetFunction:function(variable,method,param)
		{
			return function()
			{
				variable[method](param);
			}
		}
	}