var scrollElement = null;
var scrollIntervalId = null;

function StartScroll(dir, elementToScrollId)
{
    // Set the reference to the current Element to scroll
    scrollElement = document.getElementById(elementToScrollId);
    
    // Stop any previous Scrolling from other Element
    StopScroll();
    
    // Set interval to incrementally scroll the Element
    scrollIntervalId = setInterval("Scroll('" + dir + "')", 100);
}

function Scroll(dir)
{
    var left = scrollElement.scrollLeft;
    var top = scrollElement.scrollTop;

    if (dir == 'left')
        scrollElement.scrollLeft = left - 20;
    else if(dir == 'right')
        scrollElement.scrollLeft = left + 20;
    else if (dir == 'up')
        scrollElement.scrollTop = top - 20;
    else if (dir == 'down')
        scrollElement.scrollTop = top + 20;
}


function StopScroll()
{
    clearInterval(scrollIntervalId);
}