DBImage background image when picture field is empty

Hello,
I use an DBImage and a table. I want to have a standard bitmap as a content
of the DBImage
if the table field is empty. I've tried to test on field.AsBinary = Nil but
Binary is obviously not what
the compiler wants.
How do I detect this so I can load the standard bitmap only if field is
empty?

--
Kind regards
Kai Inge

{If it's not broke - don't fix it.}