How to add a field validation rule and specify an input mask

How  to add a field validation rule :

1. Open the table in Datasheet view.
2. On the Table Tools Fields tool tab, click Validation, Field Validation Rule.
3. In the Expression Builder, enter the expression that defines the rule, and then click OK.
4. On the Fields tool tab, click Validation, Field Validation Message.
5. In the Enter Validation Message dialog box, enter the message that Access displays if users enter invalid data.

How to specify an input mask :

1. Open a table in Design view.
2. Select the field you want to work with.
3. In the Input Mask property box, click the ellipsis to run the Input Mask wizard.
4. Select the mask you want to use, or click Edit List to modify a built-in mask or create one of your own.