var scrollSpeed =1;   // number of pixels to change every frame
	 var scrollDepth =200; // height of your display box
	 var scrollHeight=0;   // this will hold the height of your content
	 var scrollDelay=25;  // delay between movements.
	
	 var scrollPos=scrollDepth; // current scroll position
	 var scrollMov=scrollSpeed; // for stop and start of scroll
	
	 function doScroll() {
	  if(scrollHeight==0) getHeight();
	  scrollPos -= scrollMov;
	  if(scrollPos < (0 - scrollHeight)) scrollPos=scrollDepth;
	  document.getElementById('scrollTxt').style.top=scrollPos+'px';
	  setTimeout('doScroll();', scrollDelay);
	 }
	
	 function getHeight() {
	  scrollHeight=document.getElementById('scrollTxt').offsetHeight;
	 }
	
	 function scrMove() { scrollMov=scrollSpeed; }
	 function scrStop() { scrollMov=0; }