function my_marquee(div_name,height,direction,delay,step){
	var default_height="50";
	var marquee_obj=$(div_name);
	if (marquee_obj==null) return;
	var marquee_content=marquee_obj.innerHTML;
	marquee_obj.style.overflow="hidden";
	height=parseInt(height);
	if (height>0){
		xHeight(div_name,height);
	}
	else if(xHeight(div_name)<=0){
		xHeight(div_name,default_height);
	}
	var t1=document.createElement("div");
	var t2=document.createElement("div");
	t1.id=div_name+"_content"
	t2.id=div_name+"_content_copy"
	t1.innerHTML=marquee_content;
	//t2.innerHTML=marquee_content;
	marquee_obj.innerHTML="";
	marquee_obj.appendChild(t1);
	marquee_obj.appendChild(t2);
	//alert(marquee_obj.innerHTML);
	new Marquee(div_name,t1.id,t2.id,direction,delay,step);
}

function Marquee (demo, demo1, demo2, direction, delay, step)
{

//demo  字幕区域标签(div)的ID; 
//demo1/demo2  显示内容标签(div或td)的ID   demo1为原始内容,demo2是它的拷贝;  
//direction 字幕方向(up,down,left,right) ; 
//delay 字幕播放的延迟时间(毫秒); 
//step 字幕播放的步长(即pix,步长越小,如step=1,滚动越平滑)

	direction = direction.toLowerCase();

	if(((direction == "up" || direction == "down") && ($(demo1).offsetHeight > $(demo).offsetHeight)) || ((direction == "left" || direction == "right") && ($(demo1).offsetWidth > $(demo).offsetWidth)))
	{
		$(demo2).innerHTML = $(demo1).innerHTML;
		if(direction == "down")
			$(demo).scrollTop = 2 * $(demo1).offsetHeight - $(demo).offsetHeight;
		if(direction == "right")
			$(demo).scrollLeft = 2 * $(demo1).offsetWidth - $(demo).offsetWidth;
	}
	else
		return;
	
	var flag = true;
	var speed = delay == null? 1 : parseInt(delay);
	var amount = step == null? 1 : parseInt(step);
	var tmp_flag=1;

	var Marquee = function ()
	{
		switch(direction)
		{
			case "up":
				/*
				if($(demo2).offsetTop - $(demo).scrollTop <= 0)
					$(demo).scrollTop -= $(demo1).offsetHeight;
				else
					$(demo).scrollTop += amount;
				*/
				var s_old,s_new
				//Log.write(tmp_flag+"")
				if  (tmp_flag==1) {
					s_old=$(demo).scrollTop;
					$(demo).scrollTop += amount;
					s_new=$(demo).scrollTop;
					if (s_old==s_new){
						tmp_flag=0;
					}
				}
				else {
					s_old=$(demo).scrollTop;
					$(demo).scrollTop -= $(demo1).offsetHeight;
					s_new=$(demo).scrollTop;
					if (s_old==s_new){
						tmp_flag=1;
					}
				}
				break;
			case "down":
				if($(demo1).offsetTop - $(demo).scrollTop >= 0)
					$(demo).scrollTop += $(demo2).offsetHeight;
				else
					$(demo).scrollTop -= amount;
				break;
			case "left":
				if($(demo2).offsetWidth - $(demo).scrollLeft <= 0)
					$(demo).scrollLeft -= $(demo1).offsetWidth;
				else
					$(demo).scrollLeft += amount;
				break;
			case "right":
				if($(demo).scrollLeft <= 0)
					$(demo).scrollLeft += $(demo2).offsetWidth;
				else
					$(demo).scrollLeft -= amount;
				break;
			default:break;
		}
	}

	var timer = setInterval(Marquee,speed);

	var play = function ()
	{
		if(flag)
		{
			clearInterval(timer);
			timer = setInterval(Marquee, speed);
		}
	}

	$(demo).onmouseover = function ()
	{
		if(flag)
			clearInterval(timer);
	}

	$(demo).onmouseout = function ()
	{
		if(flag)
			timer = setInterval(Marquee, speed);
	}

	this.delay = function (s)
	{
		speed = s == null? 50 : parseInt(s);
		play();
	}

	this.step = function (s)
	{
		amount = s == null? 1 : parseInt(s);
		play();
	}

	this.start = function ()
	{
		if(!flag)
		{
			flag = true;
			play();
		}
	}

	this.stop = function ()
	{
		if(flag)
		{
			flag = false;
			clearInterval(timer);
		}
	}

	this.direction = function (s)
	{
		s = s.toLowerCase();
		if( s == direction )
			return;
		if(s == "down" && direction == "up" )
			direction = s;
		if(s == "up" && direction == "down")
			direction = s;
		if(s == "right" && direction == "left")
			direction = s;
		if(s == "left" && direction == "right")
			direction = s;
		if (s == direction)
			play();
	}
}