You can use the TripleState property to specify how a check box, toggle button, or option button will display Null values.
Note The TripleState property doesn't apply to the specified controls when they are used inside an option group control.
Setting
The TripleState property uses the following settings.
| Setting | Visual Basic | Description |
|---|---|---|
| Yes | True (–1) | The control will cycle through states for Yes, No, and Null values. The control appears dimmed (grayed) when its Value property is set to Null. |
| No | False (0) | (Default) The control will cycle through states for Yes and No values. Null values display as if they were No values. |
You can set the TripleState property by using a control's property sheet, a macro, or Visual Basic.
This property can be set in any view.