Saw a bug

[bingsizi]

            pekeUpload.obj.on('change', function() {
                pekeUpload.checkFile(pekeUpload.obj[0].files[0]);
            });
            //$(document).on("change", this.obj.selector, function() {
            //    pekeUpload.checkFile(pekeUpload.obj[0].files[0]);
            //});

on "change" event listening on document

Also, delete a file, add again, can't change to listening