$(document).ready(function(){
    scrollbar();
})
function scrollbar(param) {

    if(typeof(param) == 'undefined') {
        param = '';
    }

    var scrub_height = $(".scroll-scrub").height();
    var bar_height = $(".scroll-bar").height();
    //console.log('content:'+$('.scroll-content').height()+'.. scroll:'+$('.scroll-pane').height());
    if($('.scroll-content').height() > $('.scroll-pane').height()+20) {
        $('.scroll-bar').show();
        $(".scroll-scrub").draggable({
            containment: '.scroll-bar',
            drag: function(event,ui){
                position = $(".scroll-scrub").position();
                scrub_position = position.top;
                if(scrub_position>0) {
                    module = scrub_height
                    } else {
                    module=0
                    };
                ratio = Math.round((scrub_position+module)*100/bar_height)/100;
                content_margin = ($(".scroll-content ul"+param).height()-$('.scroll-pane').height())*ratio
                $(".scroll-content ul"+param).stop(true,true).animate({marginTop:0-content_margin},200);
            }
        });
    } else {
        $('.scroll-bar').hide();
    }
}