function Dron_ScrollBox(uid)
{
 this.scrollBox = document.getElementById(uid);
 this.scrollBoxHeight = this.scrollBox.clientHeight;
 this.scrollBoxInner = this.scrollBox.innerHTML;
 this.scrollCol = this.scrolln = 0;
 this.setScroll = function ()
 {
  this.scrollBox.scrollTop = this.scrollCol + this.scrolln;
  if(this.scrolln==this.scrollBoxHeight)
   return this.addScroll()
  else
   this.scrolln ++;
  var o = this;
  function m(){o.setScroll();}
  setTimeout(m,0);
 }
 this.addScroll = function ()
 {
//  this.scrollBox.innerHTML += "<br />" + this.scrollBoxInner;
this.scrollBox.innerHTML +=  this.scrollBoxInner;
  this.scrollCol = this.scrollBox.scrollTop;
  this.scrolln = 0;
  var o = this;
  function m(){o.setScroll();}
  setTimeout(m,1000);
 }
 this.init = this.addScroll;
}
//类的调用方法，可多个

//new Dron_ScrollBox("scrollBox2").init();