my $params = '?rm=aktualisiere';
    my %p = %{$self->session->param_hashref()};
    foreach my $key ( keys(%p) ) {
        next if $key =~ m/^_/;
        next if $key eq 'rm';
        next unless defined $p{$key};
        $p{$key} = URI::Escape::uri_escape( $p{$key} );
        $params .= "\;$key\=$p{$key}";
    }