function init()
{
    var interval = window.setInterval("scroll()", 100);
}

function scroll()
{
    //document.getElementById('scrollbar_part1').style.top = (parseInt(document.getElementById('scrollbar_part1').style.top) + 1) + "px";
    
    pos1 = parseInt(document.getElementById('scrollbar_part1').style.top);
    pos2 = parseInt(document.getElementById('scrollbar_part2').style.top);
    
    if(pos1 < 700)
        document.getElementById('scrollbar_part1').style.top = (pos1 + 1) + "px";
    else
        document.getElementById('scrollbar_part1').style.top = (-699) + "px";
        
    if(pos2 < 700)
        document.getElementById('scrollbar_part2').style.top = (pos2 + 1) + "px";
    else
        document.getElementById('scrollbar_part2').style.top = (-699) + "px";
}