function next()
{
    var scrollDiv = document.getElementById('scrollbuttoncontent');
    var divheight = scrollDiv.style.height;
    var divheight = divheight.replace('px', '');
    var current_pos = scrollDiv.scrollTop;
    scrollDiv.scrollTop = current_pos + divheight;
}

function previous()
{
    var scrollDiv = document.getElementById('scrollbuttoncontent');
    var divheight = scrollDiv.style.height;
    var divheight = divheight.replace('px', '');
    var current_pos = scrollDiv.scrollTop;    
    
    scrollDiv.scrollTop = current_pos - divheight;
}

function initScrollPosition()
{
    document.getElementById('scrollbuttoncontent').scrollTop = 0;
}