Raphael Js Drag Rotation In Firefox And Internet Explorer

I am new to the SVG and Raphael world and am trying to create a radial dial that has a draggable needle. The drag works fine in Chrome, Safari, and Opera. In Internet Explorer the

Solution 1:

I can't see where 'event' is defined, you could try amending your handler function params to take the event direct like so...

      moveNeedle = function (dx,dy,x,y,e) {

      ....

      var startDrag = function () {
            // console.log(this);
      }, 
      dragger = moveNeedle,
      endDrag = function () {};

jsfiddle

Edit: That should fix the firefox bug. For the jittery problem, I think its layerX/Y. Maybe use something like clientX/Y, eg

var mouseX = e.clientX;
           var mouseY = e.clientY;

jsfiddle