var speed=10;//速度数值越大速度越慢
  demo2.innerHTML=demo1.innerHTML;
  function Marquee()
  {
	if(demo2.offsetWidth-demo.scrollLeft<=0){demo.scrollLeft-=demo1.offsetWidth;}
	else {demo.scrollLeft++;}
  }
  var MyMar=setInterval(Marquee,speed);
  demo.onmouseover=function() {clearInterval(MyMar);}

  demo.onmouseout=function() {MyMar=setInterval(Marquee,speed);}