CustomControl.Locked Property (Access)
The Locked property specifies whether you can edit data in a control in Form view. Read/write Boolean.
The default setting of the Locked property is True. This setting allows editing, adding, and deleting data.
Use the Locked property to protect data in a field by making it read-only. For example, you might want a control to only display information without allowing editing, or you might want to lock a control until a specific condition is met.
The following example toggles the Enabled property of a command button and the Enabled and Locked properties of a control, depending on the type of employee displayed in the current record. If the employee is a manager, then the SalaryDetails button is enabled and the PersonalInfo control is unlocked and enabled.