var leftmost = 655;
var rightmost = 1355;
var interval = null;
var DOMCapable;

document.getElementById ? DOMCapable = true : DOMCapable = false;

function scrollRight(menuName)
{
var leftPosition;
if (DOMCapable)
{
leftPosition =
parseInt(document.getElementById(menuName).style.left);
if (leftPosition >= rightmost)
{
// if the menu is already fully shown, stop scrolling
clearInterval(interval);
return;
}
else
{
// else move it 10 more pixels in
leftPosition += 10;
document.getElementById(menuName).style.left = leftPosition+"px";
		}
	}
}

function scrollLeft(menuName)
{
if (DOMCapable)
{
leftPosition =
parseInt(document.getElementById(menuName).style.left);
if (leftPosition < leftmost)
{
// if menu is fully retracted, stop scrolling
clearInterval(interval);
return;
}
else
{
// else move it 10 more pixels out
leftPosition -= 10;
document.getElementById(menuName).style.left = leftPosition+"px";
		}
	}
}

function startRightScroll(menuName)
{
clearInterval(interval);
interval = setInterval('scrollRight("' + menuName + '")', 30);
}

function startLeftScroll(menuName)
{
clearInterval(interval);
interval = setInterval('scrollLeft("' + menuName + '")', 30);
}