Forum OpenACS Development: ad_form questions: combine two widgets, validate two values

How can I create a list of checkboxes that is within a widget of radio
buttons? I need this for the cal-item-create-recurrence page in calendar where
you can pick recurrence for days of week. If you choose that (among the radio
buttons), then you can pick arbitrarily many days of the week.

If you look at
http://cvs.openacs.org/cvs/*checkout*/openacs-4/packages/calendar/www/cal-item-create-recurrence.tcl?content-type=text%2Fplain&rev=1.4.8.1
you'll see that I simply put the needed html into a string and fiddle that
into ad_form's option field. I admit that this is kinda kludgey (actually
pretty kludgey), but the ad_form'ed version of this page is much better.

My second ad_form question is: How can I validate *two* fields in the
-validate section? Here's what I want to have there:

    if {![calendar::item::dates_valid_p -start_date $cal_item(start_date) -end_date $recur_until]} {
        ad_return_complaint 1 [_ calendar.start_date_before_end_date]
        ad_script_abort
    }

I don't understand the second question, plenty of forms do two-value checking...

As far as complex combinations of widgets go, it may just be easiest to write a custom widget private to the calendar package...