Alternative to offsetLeft and offsetTop?

I wrote a little canvas application and finally tried to incorporate it into my blog, however now I find that on a mouse click offsetLeft and offsetRight are always 0.

I don't really know why, but how do I get that info back?

In case anyone is not seeing the tags on this post: yes I am using jQuery for mouse events.

$('#'+canvasId).mousedown(function(e){

    that.mouse.down = true;
    that.mouse.downx = e.pageX-this.offsetLeft;
    that.mouse.downy = e.pageY-this.offsetTop;

    that.mouse.dialogDown = k.operations.interface.getHudItem(that.mouse.downx, that.mouse.downy);

    k.operations.interface.mouseDown(that.mouse.downx, that.mouse.downy);
}开发者_C百科);

Is this work?

var offset = jQuery(this).css('offset');
alert( 'Left: ' + offset.left + '\nTop: ' + offset.top );

It should be offset.left and offset.top, not offsetLeft and offsetTop.

try this

 $('#'+canvasId).mousedown(function(e){

     tt = $( this );

     tof = tt.offset()

     that.mouse.down = true;
     that.mouse.downx = e.pageX-tof.left;
     that.mouse.downy = e.pageY-tof.top;

     that.mouse.dialogDown = k.operations.interface.getHudItem(that.mouse.downx, that.mouse.downy);

k.operations.interface.mouseDown(that.mouse.downx, that.mouse.downy);
});