var timerID = null;
function ScrollUp(speed) {
  if(document.getElementById) {
   if(parseInt(txt.style.top) < 0){ txt.style.top = parseInt(txt.style.top) + speed + "px"; }
   timerID = setTimeout("ScrollUp("+speed+")",30); }
 }

function ScrollDown(speed) {
  if(document.getElementById) {                        
   if(parseInt(txt.style.top) > cnt.offsetHeight - txt.offsetHeight) { 
    txt.style.top = parseInt(txt.style.top) - speed + "px"; }
    timerID = setTimeout("ScrollDown("+speed+")",30); }
 }

function ScrollStop() {
  if(document.getElementById) {
   clearTimeout(timerID); }
 }

function ScrollInit() {
  if (document.getElementById) {
   cnt = document.getElementById("cont");
   txt = document.getElementById("text");
   txt.style.top = 0; }
 }