function slideLine(box,stf,delay,speed,h)
  {
    var slideBox = document.getElementById(box);
    var delay = delay||1000,speed = speed||20,h = h||20;
    var tid = null,pause = false;
    var s = function(){tid=setInterval(slide, speed);}
    var slide = function(){
      if(pause) return;
      slideBox.scrollTop += 1;
      if(slideBox.scrollTop%h == 0){
        clearInterval(tid);
        slideBox.appendChild(slideBox.getElementsByTagName(stf)[0]);
        slideBox.scrollTop = 0;
        setTimeout(s, delay);
      }
    }
    slideBox.onmouseover=function(){pause=true;}
    slideBox.onmouseout=function(){pause=false;}
    setTimeout(s, delay);
  }
  slideLine('headnews','div',5000,20,20);