var scrollTimer = null;

function startmoveup(clip)
    {
    if(scrollTimer)
        stop();
    scrollTimer = setInterval('moveup(\'' + clip + '\');', 20);
    }

function startmovedown(clip)
    {
    if(scrollTimer)
        stop();
    scrollTimer = setInterval('movedown(\'' + clip + '\');', 20);
    }

function stop()
    {
    clearInterval(scrollTimer);
    }