The pages on this site contain documentation for very old MS-DOS software,
purely for historical purposes.
If you're looking for up-to-date documentation, particularly for programming,
you should not rely on the information found here, as it will be woefully
out of date.
Error Message
Error 90: Ordinal expression expected
A procedure or function expected an ordinal type.
A variable passed to this procedure or function must be
of an ordinal type. An expression passed to it must
evaluate to an ordinal value.