I have a set of checkboxes on a page, coded thus:
htp.FormCheckBox (‘award_choice’, ‘A’, cattributes => ‘ID=”award”‘);
where ‘A’ is the first in a series of possible values for award_choice, which gets passed by htp.FormSubmit to the next page. With awake users things work well, but occasionally a user (the first such being myself) nods off and omits to check any of the boxes, when the next page explodes because it has a required parameter not set by the falling page/routine (which uses htp.FormHidden for the other parameters, but htp.FormCheckBox for this set.
How can I detect that the user has made such a mistake and so avoid the explosion? It must be possible, because there are many pages with checkboxes on them.
