The exclGroup object describes a mutual
exclusion relationship between a set of containers.
An exclusion group is used to cause a set of radio buttons boxes
to be mutually exclusive. When a user activates one member of the
set, the other members are automatically deactivated. For example,
if the set consists of radio buttons, clicking one button causes
the other buttons to be deactivated.
Each member of the exclusion group is associated with an on value
and an off value. When a member is activated, it
assumes the on value. When it is deactivated, it
assumes the off value. The on value
for each member of a particular exclusion group must be unique.
Selecting one member of the exclusion group in the form causes
each member’s value to be set to its on or off value,
as appropriate. Similarly, assigning the on value
to a member of the exclusion group causes the other members to be deactivated.
Alternatively, a value may be assigned to the exclusion group
itself. In this case, each member is activated only if the value
matches the on value for that member.
