defaultStep=5
step=defaultStep 
function scrollDivDown(id){
   clearTimeout(timerDown) 
   document.getElementById(id).scrollTop+=step 
   timerDown=setTimeout("scrollDivDown('"+id+"')",10)
} 
function scrollDivUp(id){
   clearTimeout(timerUp)
   document.getElementById(id).scrollTop-=step 
   timerUp=setTimeout("scrollDivUp('"+id+"')",10)
} 
timerDown="" 
timerUp="" 
function stopMe(){
   clearTimeout(timerDown) 
   clearTimeout(timerUp)
}
document.onmousemove=function(){stopMe()}