function initScroll() {
    //change the main div to overflow-hidden as we can use the slider now
    $('#scroll-pane').css('overflow','hidden');

    //compare the height of the scroll content to the scroll pane to see if we need a scrollbar
    var difference = $('#scroll-content').height()-$('#scroll-pane').height();//eg it's 200px longer
    if(difference>0)//if the scrollbar is needed, set it up...
    {
       var proportion = difference / $('#scroll-content').height();//eg 200px/500px
       var handleHeight = Math.round((1-proportion)*$('#scroll-pane').height());//set the proportional height - round it to make sure everything adds up correctly later on
       handleHeight -= handleHeight%2;

       $("#scroll-pane").after('<\div id="slider-wrap"><\div id="slider-vertical"><\/div><\/div>');//append the necessary divs so they're only there if needed
       $("#slider-wrap").height($("#scroll-pane").height());//set the height of the slider bar to that of the scroll pane


       //set up the slider
       $('#slider-vertical').slider({
          orientation: 'vertical',
          min: 0,
          max: 100,
          value: 100,
          slide: function(event, ui) {//used so the content scrolls when the slider is dragged
             var topValue = -((100-ui.value)*difference/100);
             $('#scroll-content').css({top:topValue});//move the top up (negative value) by the percentage the slider has been moved times the difference in height
          },
          change: function(event, ui) {//used so the content scrolls when the slider is changed by a click outside the handle or by the mousewheel
             var topValue = -((100-ui.value)*difference/100);
             $('#scroll-content').css({top:topValue});//move the top up (negative value) by the percentage the slider has been moved times the difference in height
          }
       });

       //set the handle height and bottom margin so the middle of the handle is in line with the slider
       $(".ui-slider-handle").css({height:handleHeight,'margin-bottom':-0.5*handleHeight});

       var origSliderHeight = $("#slider-vertical").height();//read the original slider height
       var sliderHeight = origSliderHeight - handleHeight ;//the height through which the handle can move needs to be the original height minus the handle height
       var sliderMargin =  (origSliderHeight - sliderHeight)*0.5;//so the slider needs to have both top and bottom margins equal to half the difference
       $(".ui-slider").css({height:sliderHeight,'margin-top':sliderMargin});//set the slider height and margins

    }//end if

    $(".ui-slider").click(function(event){//stop any clicks on the slider propagating through to the code below
            event.stopPropagation();
       });

    $("#slider-wrap").click(function(event){//clicks on the wrap outside the slider range
              var offsetTop = $(this).offset().top;//read the offset of the scroll pane
              var clickValue = (event.pageY-offsetTop)*100/$(this).height();//find the click point, subtract the offset, and calculate percentage of the slider clicked
              $("#slider-vertical").slider("value", 100-clickValue);//set the new value of the slider
    });

    //additional code for mousewheel
    $("#scroll-pane,#slider-wrap").mousewheel(function(event, delta){
            var speed = 5;
            var sliderVal = $("#slider-vertical").slider("value");//read current value of the slider

            sliderVal += (delta*speed);//increment the current value

            $("#slider-vertical").slider("value", sliderVal);//and set the new value of the slider

            event.preventDefault();//stop any default behaviour
    });

}