var scroll_handler = 0;
        var scroll_start = function(){ if(!scroll_handler) { scroll_handler = window.setInterval(scroll_step,60); } }
        var scroll_stop  = function(){ if(scroll_handler) { window.clearInterval(scroll_handler); scroll_handler = 0; } }
        var scroll_step  = function() {
            if (!scroll_handler) return;
            var avail_height = jQuery("#scroll")[0].scrollHeight;
            var child_height = jQuery("#scroll .scroll_content")[0].scrollHeight;
            var d = jQuery("#scroll .scroll_content");
            var offset = parseInt( d.css("margin-top") );
            if (child_height + offset + 24 > avail_height) { d.css({ marginTop: offset - 5 }); } else scroll_stop();
        }
        jQuery(function(){
            jQuery("#scroll .scroll_content").css({marginTop:0});
            jQuery("#scroll_top").mousedown(function(){ jQuery("#scroll .scroll_content").css({marginTop:0}) });
            jQuery("#scroll_down").mouseup(scroll_stop).mouseout(scroll_stop).mousedown(scroll_start);
        });