for($i = $self->{'Count'}; $i > 1; $i--) {
        $j = $i - 1;
            $next = "${currn}." . $i . $ext;
            $prev = "${currn}." . $j . $ext;
        if ( -r $prev && -f $prev ) {
            move($prev,$next)	## move will attempt rename for us
                or croak "error: move failed: ($prev,$next)";
        }
    }