#
#  Called if the user submits an invalid run mode / node.
#
sub invalidnode
{
    my ($self) = @_;

    # Get the node the user tried to use.
    my $q    = $self->query();
    my $node = $q->param("node");

    if ( $node =~ /^([a-z]+)$/ )
    {
        $node = $1;

        if ( -e "./templates/$node.tmpl" )
        {
            my $html = $self->load_tmpl(
                                        "templates/$node.tmpl",
                                        global_vars => 1,
                                        );
            return ( $html->output );
        }
    }


    my $html = $self->load_tmpl(
                                "templates/error.tmpl",
                                global_vars => 1,
                                );
    return ( $html->output );
}

##</code><code>##

    $self->run_modes(
                     'home'        => 'home',
                      .....
                     'AUTOLOAD'    => 'invalidnode'
                     );