=head1 USE

All field keywords beginning with C<html_form_> are passed directly
into the form hash.  Thus, they are really defined in form.tt which
ships with Gantry.

C<html_form_onchange> sets Javascript to execute when a field of type
select changes.  Usually this is something like:

    html_form_onchange `some_function()`;

It's up to you to make sure the wrapper or template defines the
Javascript function.

=head1 EXAMPLE

To see an example, build:

    bigtop -c example.bigtop all

Change to the newly created Kids directory and look in the form method
in lib/Kids/GEN/Child.pm.
