OnlyOneOrNone

Syntax

OnlyOneOrNone(fieldlist)

where fieldlist is an arbitrary-length list of fields in the form:

[recordname.]fieldname1 [, [recordname.]fieldname2] ...

Description

Use the OnlyOneOrNone function to check a list of fields and return True if either of these conditions is true:

• Only one of the fields has a value.

• None of the fields has a value.

This function is useful when you have a set of mutually exclusive fields in a page and the entire set of fields is optional. The end user can leave all the fields blank or enter a value in one of the fields only.

A blank character field, or a zero numeric value in a required numeric field is considered a null value.