function scrolling(objId,sec1,sec2,speed,height){
  this.objId=objId;
  this.sec1=sec1;
  this.sec2=sec2;
  this.speed=speed;
  this.height=height;
  this.h=0;
  this.div=document.getElementById(this.objId);
  this.htmltxt=this.div.innerHTML;
  this.div.innerHTML=this.htmltxt+this.htmltxt;
  this.div.isover=false;
  this.div.onmouseover=function(){this.isover=true;}
  this.div.onmouseout=function(){this.isover=false;}
  var self=this;
  this.div.scrollTop=0;
  window.setTimeout(function(){self.play()},this.sec1);
}
scrolling.prototype={
  play:function(){
    var self=this;
    if(!this.div.isover){
      this.div.scrollTop+=this.speed;
      if(this.div.scrollTop>this.div.scrollHeight/2){
        this.div.scrollTop=0;
      }else{
        this.h+=this.speed;
        if(this.h>=this.height){
          if(this.h>this.height|| this.div.scrollTop%this.height !=0){
            this.div.scrollTop-=this.h%this.height;
          }
          this.h=0;
          window.setTimeout(function(){self.play()},this.sec1);
          return;
        }
      }
    }
    window.setTimeout(function(){self.play()},this.sec2);
  }, 
  prev:function(){
    if(this.div.scrollTop == 0)
    this.div.scrollTop = this.div.scrollHeight/2;
    this.div.scrollTop -= this.height;
  },
  next:function(){
    if(this.div.scrollTop ==  this.div.scrollHeight/2)
    this.div.scrollTop =0;
    this.div.scrollTop += this.height;
  }
};