var speed = 1; // change scroll speed with this value
/**
 * Initialize the marquee, and start the marquee by calling the marquee function.
 */
function init(){
  var el = document.getElementById("marquee_replacement");
  if (el) el.style.overflow = 'hidden';
  scrollFromBottom();
}

var go = 0;
/**
 * This is where the scroll action happens.
 * Recursive method until stopped.
 */
function scrollFromBottom(){
  var el = document.getElementById("marquee_replacement");
  if (el) {
     if(el.scrollTop >= el.scrollHeight-150){
       el.scrollTop = 0;
     };
     el.scrollTop = el.scrollTop + speed;
     if(go == 0){
       setTimeout("scrollFromBottom()",50);
     };
  }
}

/**
 * Set the stop variable to be true (will stop the marquee at the next pass).
 */
function stop(){
  go = 1;
}

/**
 * Set the stop variable to be false and call the marquee function.
 */
function startit(){
  go = 0;
  scrollFromBottom();
}