var scrollTick = 2;

var scrollHeight = 420;

var scrollTimerSpeed = 30;

var scrollTimer = setTimeout("");



function scrollUp() {

	if ( document.getElementById ) {

		clearScroll();

		scrollTimer = setTimeout("doScrollUp()", scrollTimerSpeed);

	}

}



function scrollDown() {

	if ( document.getElementById ) {

		clearScroll();

		scrollTimer = setTimeout("doScrollDown()", scrollTimerSpeed);

	}

}



function doScrollUp() {

	var scrollClip=document.getElementById("scrollClip");

	if ( parseInt(scrollClip.style.top) < 0 ) {

		scrollClip.style.top = Math.min (parseInt(scrollClip.style.top) + scrollTick, 0);

	}

	scrollTimer = setTimeout("doScrollUp()", scrollTimerSpeed);

}



function doScrollDown() {

	var scrollClip=document.getElementById("scrollClip");

	if ( parseInt(scrollClip.offsetHeight)+parseInt(scrollClip.style.top) > scrollHeight ) {

		scrollClip.style.top = parseInt(scrollClip.style.top) - scrollTick;

	}

	scrollTimer = setTimeout("doScrollDown()", scrollTimerSpeed);

}



function clearScroll() {

	clearTimeout(scrollTimer);



}



window.onload=function() {

	if ( document.getElementById ) {

		var scrollClip=document.getElementById("scrollClip");

		if ( parseInt(scrollClip.offsetHeight) > scrollHeight ) {

//			alert("they are going on!");

//			document.getElementById("arrows").style.visible = true;

			document.getElementById("arrows").style.visibility = "visible";

		}

	}

}