Scroll文字滚动js

function ScrollImgLeft(){
var speed=50,
	doc=document,
	scroll_begin = doc.getElementById("scroll_begin"),
	scroll_end = doc.getElementById("scroll_end"),
	scroll_div = doc.getElementById("scroll_div");
scroll_end.innerHTML=scroll_begin.innerHTML;
  function Marquee(){
	if(scroll_end.offsetTop-scroll_div.scrollTop<=0)
	  scroll_div.scrollTop-=scroll_begin.offsetHeight
	else
	  scroll_div.scrollTop++
  }
var MyMar=setInterval(Marquee,speed)
  scroll_div.onmouseover=function() {clearInterval(MyMar)}
  scroll_div.onmouseout=function() {MyMar=setInterval(Marquee,speed)}
}
ScrollImgLeft();