filename return undefine on Chrome

[GoogleCodeExporter]

code:
$(document).ready(function() {
    uploader = $("input[name=upload]").upload({
         name: 'file',
         method: 'post',
         action: 'upload.php',
         enctype: 'multipart/form-data',
         onSubmit: function() {

         },
         onSelect: function() { 
             alert(uploader.filename());
         },
         onComplete: function(data) {
             $("form[target^='iframe']")[0].reset();
         }
    });
    uploader.autoSubmit = false;
});

onSelect call uploader.filename(), it return undefine...
anyone know what going wrong? 

Original issue reported on code.google.com by loberGlog@gmail.com on 6 Oct 2014 at 7:04