event.offsetX in Firefox

Answer 1

But , what you will do if there is not layerX,layerY fields ?

 var xe=e.offsetX,ye=e.offsetY;
  if(!xe){
     xe=e.clientX - $(e.target).offset().left;
  }
  if(!ye){
    ye= e.clientY - $(e.target).offset().top;
  }