defaultStep=1
step=defaultStep

function scrollDivDown( id )
{
   document.getElementById(id).scrollTop+=step;
   timerDown=setTimeout("scrollDivDown('"+id+"')",10);
}

function scrollDivUp( id )
{
   document.getElementById(id).scrollTop-=step;
   timerUp=setTimeout("scrollDivUp('"+id+"')",10);
}