public static function validateUpload($FILE_DESCRIPTOR, $SAFETY_CHECK=true)
    {
        $retval = true;
        $filename = isset($FILE_DESCRIPTOR['name']) ? basename($FILE_DESCRIPTOR['name']) : false;

        if ( $FILE_DESCRIPTOR['error'] == 1) {
            $retval = _m("General upload failure");
        } else if ( $FILE_DESCRIPTOR['error'] == 4) {
            $retval = _m('Missing file, make sure to select file(s) before pressing submit');
        } else if ( $filename === false ) {
            $retval = _m("Uploaded file has no name");
        } else if ( $FILE_DESCRIPTOR['size'] < 1 ) {
            $retval = _m("File is empty: ").$filename;
        } else if ( $FILE_DESCRIPTOR['error'] == 0 ) {
            if ( $SAFETY_CHECK && preg_match(self::BAD_FILE_SUFFIXES, $filename) ) $retval = _m("File suffix not allowed");
        } else {
            $retval = _m("Upload failure=").$FILE_DESCRIPTOR['error'];
        }
        return $retval;
    }