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

//wrap an extra div around the scrollpane so we can use the mousewheel later
$(this).wrap('<\div class="scroll-container">');

//compare the height of the scroll content to the scroll pane to see if we need a scrollbar
var difference = $(this).find('.scroll-content').height()-$(this).height();//eg it's 200px longer 

if(difference>0)//if the scrollbar is needed, set it up...
{
   var proportion = difference / $(this).find('.scroll-content').height();//eg 200px/500px

   var handleHeight = Math.round((1-proportion)*$(this).height());//set the proportional height - round it to make sure everything adds up correctly later on
   handleHeight -= handleHeight%2; 

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


   //set up the slider 
   $(this).next().find('.slider-vertical').slider({
      orientation: 'vertical',
      min: 0,
      max: 100,
      value: 100,
      slide: function(event, ui) {
         var topValue = -((100-ui.value)*difference/100);
         $(this).parent().prev('.scroll-pane').find('.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) {
         var topValue = -((100-ui.value)*difference/100);
         $(this).parent().prev('.scroll-pane').find('.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
   $(this).next().find(".ui-slider-handle").css({height:handleHeight,'margin-bottom':-0.5*handleHeight});
   var origSliderHeight = $(this).next().find(".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
   $(this).next().find(".ui-slider").css({height:sliderHeight,'margin-top':sliderMargin});//set the slider height and margins


}//end if
	
	//code for clicks on the scrollbar outside the slider
	$(".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
	  	$(this).find(".slider-vertical").slider("value", 100-clickValue);//set the new value of the slider
	}); 
	 
	//additional code for mousewheel
	$(this).parent().mousewheel(function(event, delta){
  		var speed = 15;
	    var sliderVal = $(this).find(".slider-vertical").slider("value");//read current value of the slider
		
	    sliderVal += (delta*speed);//increment the current value
 
	    $(this).find(".slider-vertical").slider("value", sliderVal);//and set the new value of the slider
		
	    event.preventDefault();//stop any default behaviour
 	});
	
	
});//end each
	
});