[jQuery] get image size?

[heohni]

I haveing an issue with this:

$("#ver_bildname").change(function () {
var width = $(this).width();
alert(width);
});

returns always 272?
Whatever picture I try, the answer is alsway 272.

$(this).val(); returns me the correct name,
var ext = $('#ver_bildname').val().split('.').pop().toLowerCase(); the
coorect file extension....

How can I get the current image size?

THANKS!!