[jQuery] Jquery makes two ajax requests in one!!

[jQuery] Jquery makes two ajax requests in one!!


I have a strange problem. I have to do an ajax request after a select
box changes (change event) so i have the following code:
$('#comprensori_id').change(function() {
            var comprensorio_id = $(this).val();
            $.ajax({
                 type: "GET",
                 url: "",
                 data: "comprensorio_id=" + comprensorio_id,
                 success: function(data, msg){
                $('#comuni_id').empty();
                $('#comuni_id').append(data);
                 }
                 });
        });
the problem is that when i change the select box selection my browser
makes two consecutives same ajax request and i can't figure out
why...this is very strange