function scrollText(id, start, end)
{
    var text = document.getElementById(id);
    
    if(text.style.left === '') text.style.left = start + 'px';
    
    if ( text )
    {
        var pos = moveText(id, -2);

        if ( pos < end ) text.style.left = start + 'px';
    }
}

function moveText(id, amount)
{
    var text = document.getElementById(id);
    var oldleft = text.style.left.substring(0,text.style.left.indexOf('p'));
    var newleft = parseInt(oldleft) + amount; 
    text.style.left = newleft + 'px';
    return newleft;
}