CHECK vs BEFORE trigger

Hi All,

I am about to create a new table that will store among other things two
dimensions.  The user requires that the smaller of the two dimesions always be
referred to as the width.

As I see it I can either implement a CHECK constraint and handle the error or
implement a BEFORE INSERT OR UPDATE trigger that checks the two values and
switches them if necessary.

If I implement the trigger is there any point in implementing the CHECK?

In this simple situation is there any reason to implement the CHECK and not
use a trigger?

Your comments will be appreciated.

Kind Regards,
Keith