var SPEED = 3;

function ScrollDown(ELEM){
    if(typeof ELEM == 'string')
        ELEM = document.getElementById(ELEM);

    if(ELEM)
        ELEM.scrolling = setInterval(function(){ELEM.scrollTop+=SPEED;}, 20);
}

function ScrollUp(ELEM){
    if(typeof ELEM == 'string')
        ELEM = document.getElementById(ELEM);

    if(ELEM)
        ELEM.scrolling = setInterval(function(){ELEM.scrollTop-=SPEED;}, 20);
}

function StopScroll(ELEM){
    if(typeof ELEM == 'string')
        ELEM = document.getElementById(ELEM);

    if(ELEM)
        clearInterval(ELEM.scrolling);
}