Currently, required form fields must be considered in
several places:

 - the hidden "@required" input field
 - the th elements

It would be possible to define the required fields
(e.g. in the opening <form> tag), and then reuse this
information

 - to automatically highlight the labels for the fields
 - to hand over the info to roundup (like it is already
done), and
 - to check for empty fields with Javascript before
sending the request, putting the focus to the first
field which lacked a required value.

Patch following :-)