var stepSize=2;
var delay=20;
var scrollDown=true;
var scrollUp=true;
var direction=false;

function scroller(){
		var frameHeight=parseInt(document.getElementById("frame").offsetHeight);
		var scrollerHeight=parseInt(document.getElementById("scroll").offsetHeight);
		var scrollerPos=parseInt(document.getElementById("scroll").style.top);
		if (direction=="down"){
			 if (scrollerHeight-frameHeight+scrollerPos>0){
			 		document.getElementById("scroll").style.top=parseInt(document.getElementById("scroll").style.top)-stepSize+"px";
					document.getElementById("up").style.visibility="visible";
					startTimer();
			 } else {
			 	  document.getElementById("down").style.visibility="hidden";
			 };
		} else if (direction=="up") {
			 if (scrollerPos<0){
			 		document.getElementById("scroll").style.top=parseInt(document.getElementById("scroll").style.top)+stepSize+"px";
					document.getElementById("down").style.visibility="visible";
					startTimer();
			 } else {
			 	  document.getElementById("up").style.visibility="hidden";
			 };
		};
};

function startTimer(){
				setTimeout("scroller()", delay);
};

function testforscroll(){
		var frameHeight=parseInt(document.getElementById("frame").offsetHeight);
		var scrollerHeight=parseInt(document.getElementById("scroll").offsetHeight);
  	if (frameHeight>=scrollerHeight){
 	  	 document.getElementById("up").style.visibility="hidden";
 	  	 document.getElementById("down").style.visibility="hidden";	
		};
};