sub get_branch_function {
    my $query = shift;

# get all three levels of keys into variables,
# setting defaults as necessary:
    my $action  = $query->param('action') ? $query->param('action') : 'default';
    my $confirm = $query->param('confirm') ? 'confirm' : 'default';
    my $commit  = $query->param('commit')  ? 'commit' : 'default';

# set up the hash so that whatever combination of keys
# it gets, it will produce a value:
    my %dispatch = (
        add => {
            confirm => {
                commit  => \&commit_dialog,
                default => \&add_dialog,
            },
            default => {
                commit  => \&add_dialog,
                default => \&add_dialog,
            },
        },
        remove => {
            confirm => {
                commit  => \&commit_dialog,
                default => \&confirm_dialog,
            },
            default => {
                commit  => \&choose_dialog,
                default => \&choose_dialog,
            },
        },
        modify => {
            confirm => {
                commit  => \&commit_dialog,
                default => \&confirm_dialog,
            },
            default => {
                commit  => \&choose_dialog,
                default => \&choose_dialog,
            },
        },
        default => {
            confirm => {
                commit  => \&action_dialog,
                default => \&action_dialog,
            },
            default => {
                commit  => \&action_dialog,
                default => \&action_dialog,
            },
        },
    );

# now one step should return the right subroutine:
    return $dispatch{ $action }{ $confirm }{ $default };

}