function startScrollerHelp() {

   var track_vert = $('helptrack').getCoordinates();

   var mySlide_vert = new Slider($('helptrack'), $('helphandle'), {
         steps: track_vert['height'],
         mode: 'vertical',
         onChange: function(step){
            var scrollable_vert = $('help-contain');
            var offset_vert = scrollable_vert.getSize();
            scrollable_vert.scrollTo(0, Math.abs(Math.round(step/track_vert['height']*(offset_vert['scrollSize']['y']-offset_vert['size']['y']))));
         }
      }).set(0);   
}