Microsoft Access - Display Default Text When A Field Is Null (Access 97/2000/2002/2003)
You can use a field's Format property to display default text information that is unavailable or unknown. To do so, set the Format property to:
- @;"Your Default Text"
As you can see, the format consists of two sections separated by a semicolon. The string specified in the second section appears when the field is Null or contains a zero-length string. Note that you can set the Format property at both the control and field level.