Scroll virker ikke i FireFox

Hej,

På www.mountfield.dk/realtime har jeg implementeret en funktion til at scrolle en div. Denne er vist herunder:

function scrollayer(layername,amt,tim)
{
  thelayer = getElement(layername);
  if (!thelayer) return;
  amount = amt;
  theTime = tim;
  realscroll();
}

function realscroll()
{
  clipTop += amount;
  clipBottom += amount;
  topper -= amount;
   
  if (clipTop < 0 || clipBottom > lyrheight)
  {
    clipTop -= amount;
    clipBottom -= amount;
    topper += amount;
    return;
  }
  if (document.getElementById || document.all)
  {
    clipstring = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
    thelayer.style.clip = clipstring;
    thelayer.style.top = topper;
  }
  else if (document.layers)
  {
    thelayer.style.clip.top = clipTop;
    thelayer.style.clip.bottom = clipBottom;
    thelayer.style.top = topper;
  }
  time = setTimeout('realscroll()',theTime);
}

function stopScroll()
{
  if (time) clearTimeout(time);
}

Desværre virker det ikke for FireFox.

Mvh, Steven