HTML5 with jQuery - e.offsetX is undefined in Firefox

In my HTML5 page, I have a div with mousemove event as follows:

$('#canvas').mousemove(function(e){
	xpos = e.offsetX;
	ypos = e.offsetY;
	$('#mouse').html("X : " + xpos + " ; Y : " + ypos);
});

It works fine with Google Chrome. But in Firefox, both the are giving the value undefined. I have checked it by using Firebug, that is, logged the e object to console. Both offsetX and offsetY are found to be undefined.

When I searched in Google, there was a solution saying I should use layerX and layerY, if both offsetX and offsetY are undefined. But from Firebug, I was not able to find it. And even I had given it a try like this:

xpos = (e.offsetX==undefined)?e.layerX:e.offsetX;
ypos = (e.offsetY==undefined)?e.layerY:e.offsetY;

But that's also giving undefined as values.

I am using the most recent jQuery - v1.8.2. And I am testing in my Firefox v14.0.1

Any ideas or suggestions?

---

EDIT

Thanks to dystroy and vusan for helping me. The solution to the above issue is as follows:

SOLUTION

$('#canvas').mousemove(function(e){
  $('#cursor').show();
  if(e.offsetX==undefined) // this works for Firefox
  {
    xpos = e.pageX-$('#canvas').offset().left;
    ypos = e.pageY-$('#canvas').offset().top;
  }				
  else                     // works in Google Chrome
  {
    xpos = e.offsetX;
    ypos = e.offsetY;
  }
  $('#mouse').html("X : " + xpos + " ; Y : " + ypos);
});

Try using layerX and layerY for Firefox and offsetX for other browser.

If event fired with jquery:

xpos = e.offsetX === undefined ? e.originalEvent.layerX : e.offsetX;
ypos = e.offsetY === undefined ? e.originalEvent.layerY : e.offsetY;

If event fired with javascript:

xpos = e.offsetX==undefined?e.layerX:e.offsetX;
ypos = e.offsetY==undefined?e.layerY:e.offsetY;

Use layerX and layerY in FF and offsetX and offsetY in all other browsers.

$('#canvas').mousemove(function(e){
  xpos = e.offsetX === undefined ? e.originalEvent.layerX : e.offsetX;
  ypos = e.offsetY === undefined ? e.originalEvent.layerY : e.offsetY;

  $('#mouse').html("X : " + xpos + " ; Y : " + ypos);
});

You did not find them because its in the originalEvent. try: e.originalEvent.layerX e.originalEvent.layerY

About the pageX and pageY they are not calculating the same thing. layerX is the left of the object from the first relative/absolute parent. pageX is the left of the object from the page.

This works fine in firefox and others.

var offsetRequired = (e.offsetX || e.pageX - $(e.target).offset().left);

Firefox actually does support MouseEvent.offsetX and MouseEvent.offsetY after release 39.0, which is released in july 2015.