var scrollTimer = null;
var mySlide     = null;    
function scrollRepeater(dir)
{
  if ( dir == 'scrollUp' )
    mySlide.set(mySlide.step-7);
  else
    mySlide.set(mySlide.step+7);
  scrollTimer = (function() { scrollRepeater(dir) }).delay(10);
}

function scrollStart(event)
{
  var event = new Event(event);
  scrollRepeater(event.target.id);
}

function stopScrolling()
{
  scrollTimer = $clear(scrollTimer);
}