function ScrollText(content,btnPrevious,btnNext,autoStart)
{
    this.Delay = 10;
    this.LineHeight = 20;
	this.Amount = 1;//注意:LineHeight一定要能整除Amount.
	this.Direction = "up";
    this.Timeout = 2000;
    this.ScrollContent = this.$(content);
    this.ScrollContent.innerHTML += this.ScrollContent.innerHTML;
    //this.ScrollContent.scrollTop = 0;
    if(btnNext)
    {
        this.NextButton = this.$(btnNext);
        this.NextButton.onclick = this.GetFunction(this,"Next");
        this.NextButton.onmouseover = this.GetFunction(this,"Stop");
        this.NextButton.onmouseout = this.GetFunction(this,"Start");
    }
    if(btnPrevious)
    {
        this.PreviousButton = this.$(btnPrevious);
        this.PreviousButton.onclick = this.GetFunction(this,"Previous");
        this.PreviousButton.onmouseover = this.GetFunction(this,"Stop");
        this.PreviousButton.onmouseout = this.GetFunction(this,"Start");
    }
    this.ScrollContent.onmouseover = this.GetFunction(this,"Stop");
    this.ScrollContent.onmouseout = this.GetFunction(this,"Start");
    if(autoStart)
    {
        this.Start();
    }
}

ScrollText.prototype.$ = function(element)
{
    return document.getElementById(element);
}

ScrollText.prototype.Previous = function()
{
    clearTimeout(this.AutoScrollTimer);
    clearTimeout(this.ScrollTimer);
    this.Scroll("up");
}

ScrollText.prototype.Next = function()
{
    clearTimeout(this.AutoScrollTimer);
    clearTimeout(this.ScrollTimer);
    this.Scroll("down");
}

ScrollText.prototype.Start = function()
{
    clearTimeout(this.AutoScrollTimer);
    this.AutoScrollTimer = setTimeout(this.GetFunction(this,"AutoScroll"), this.Timeout);
}

ScrollText.prototype.Stop = function()
{
    clearTimeout(this.ScrollTimer);
    clearTimeout(this.AutoScrollTimer);
}

ScrollText.prototype.AutoScroll = function()
{
    if(this.Direction == "up")
    {
        if(parseInt(this.ScrollContent.scrollTop) >= parseInt(this.ScrollContent.scrollHeight) / 2)
        {
            this.ScrollContent.scrollTop = 0;
        }
        this.ScrollContent.scrollTop += this.Amount;
    }
    else
    {
        if(parseInt(this.ScrollContent.scrollTop) <= 0)
        {
            this.ScrollContent.scrollTop = parseInt(this.ScrollContent.scrollHeight) / 2;
        }
        this.ScrollContent.scrollTop -= this.Amount;
    }
    if(parseInt(this.ScrollContent.scrollTop) % this.LineHeight != 0)
    {
        this.ScrollTimer = setTimeout(this.GetFunction(this,"AutoScroll"), this.Delay);
    }
    else
    {
        this.AutoScrollTimer = setTimeout(this.GetFunction(this,"AutoScroll"), this.Timeout);
    }
}

ScrollText.prototype.Scroll = function(direction)
{
    if(direction=="up")
    {
        if(this.ScrollContent.scrollTop == 0)
        {
            this.ScrollContent.scrollTop = parseInt(this.ScrollContent.scrollHeight) / 2;
        }
        this.ScrollContent.scrollTop -= this.Amount;
    }
    else
    {
        this.ScrollContent.scrollTop += this.Amount;
    }
    if(parseInt(this.ScrollContent.scrollTop) >= parseInt(this.ScrollContent.scrollHeight) / 2)
        {
            this.ScrollContent.scrollTop = 0;
        }
    if(parseInt(this.ScrollContent.scrollTop) % this.LineHeight != 0)
    {
        this.ScrollTimer = setTimeout(this.GetFunction(this,"Scroll",direction), this.Delay);
    }
}

ScrollText.prototype.GetFunction = function(variable,method,param)
{
    return function()
    {
        variable[method](param);
    }
}

// 图片等比例缩放
function DrawImage(ImgD,iwidth,iheight) {
     var image=new Image();
     image.src=ImgD.src;
     if(image.width>0 && image.height>0){
        if(image.width/image.height>= iwidth/iheight){
           if(image.width>iwidth){
               ImgD.width=iwidth;
               ImgD.height=(image.height*iwidth)/image.width;
           }else{
                  ImgD.width=image.width;
                  ImgD.height=image.height;
                }
               ImgD.alt=image.width+"×"+image.height;
        }
        else{
                if(image.height>iheight){
                       ImgD.height=iheight;
                       ImgD.width=(image.width*iheight)/image.height;
                }else{
                        ImgD.width=image.width;
                        ImgD.height=image.height;
                     }
                ImgD.alt=image.width+"×"+image.height;
            }
　　　　　ImgD.style.cursor= "pointer"; //改变鼠标指针
//　　　　　ImgD.onclick = function() { window.open(this.src);} //点击打开大图片
　　　　if (navigator.userAgent.toLowerCase().indexOf("ie") > -1) { //判断浏览器，如果是IE
　　　　　　ImgD.title = "请使用鼠标滚轮缩放图片，点击图片可在新窗口打开";
　　　　　　ImgD.onmousewheel = function img_zoom() //滚轮缩放
　　　　　 {
　　　　　　　　　　var zoom = parseInt(this.style.zoom, 10) || 100;
　　　　　　　　　　zoom += event.wheelDelta / 12;
　　　　　　　　　　if (zoom> 0)　this.style.zoom = zoom + "%";
　　　　　　　　　　return false;
　　　　　 }
　　　 } else { //如果不是IE
　　　　　　　     ImgD.title = "点击图片可在新窗口打开";
　　　　　　   }
    }
}



 function DrawImage2(ImgD,FitWidth,FitHeight){     
 var image=new Image();     
 image.src=ImgD.src;     
 if(image.width>0 && image.height>0){        
 	if(image.width/image.height>= FitWidth/FitHeight){             
 		if(image.width>FitWidth){                 
	 		ImgD.width=FitWidth;                 
	 		ImgD.height=(image.height*FitWidth)/image.width;             
 		}else{                 
 			ImgD.width=image.width;                 
 			ImgD.height=image.height;             
 		}         
 	} else{             
 		if(image.height>FitHeight){                 
 			ImgD.height=FitHeight;                 
 			ImgD.width=(image.width*FitHeight)/image.height;             
 		}else{                 
 			ImgD.width=image.width;                 
 			ImgD.height=image.height;             
 		}         
 	}     
 } 
 }