function scrollUp(div_id){
	var top = jQuery("#" + div_id).scrollTop();
	var height = jQuery("#" + div_id).height();
	var nextTop = parseInt(top) - parseInt(height);	
	jQuery("#" + div_id).scrollTop(nextTop);
}

function scrollDown(div_id){
	var top = jQuery("#" + div_id).scrollTop();
	var height = jQuery("#" + div_id).height();
	var nextTop = parseInt(top) + parseInt(height);	
	jQuery("#" + div_id).scrollTop(nextTop);
}