LimitToList Property [Access 2003 VBA Language Reference]
You can use the LimitToList property to limit a combo box's values to the listed items. Read/write Boolean.
expression Required. An expression that returns one of the objects in the Applies To list.
The LimitToList property uses the following settings.
|Yes||True||If the user selects an item from the list in the combo box or enters text that matches a listed item, Microsoft Access accepts it. If the entered text doesn't match a listed item, the text isn't accepted and the user must then retype the entry, select a listed item, press ESC, or click Undo on the Edit menu.|
|No||False||(Default) Microsoft Access accepts any text that conforms to the ValidationRule property.|
When the LimitToList property of a bound combo box is set to No, you can enter a value in the combo box that isn't included in the list. Microsoft Access stores the new value in the form's underlying table or query (in the field specified in the combo box's ControlSource property), not the table or query set for the combo box by the RowSource property. To have newly entered values appear in the combo box, you must add the new value to the table or query set in the RowSource property by using a macro or Visual Basic event procedure that runs when the NotInList event occurs.
Note If you set the combo box's BoundColumn property to any column other than the first visible column (or if you set BoundColumn to 0), the LimitToList property is automatically set to Yes.
Setting both the LimitToList property and the AutoExpand property to Yes lets Microsoft Access find matching values from the list as the user enters characters in the text box portion of the combo box, and restricts the entries to only those values.
When the LimitToList property is set to Yes and the user clicks the arrow next to the combo box, Microsoft Access selects matching values in the list as the user enters characters in the text box portion of the combo box, even if the AutoExpand property is set to No. If the user presses ENTER or moves to another control or record, the selected value appears in the combo box.
Combo boxes accept Null values when the LimitToList property is set to Yes or True, whether or not the list contains Null values. If you want to prevent users from entering a Null value in a combo box, set the Required property of the field in the table to which the combo box is bound to Yes.
The following example limits a given combo box's values to its listed items.
Forms("Order Entry").Controls("States").LimitToList = True