True if Microsoft Excel displays certain alerts and messages while a macro is running. Read/write Boolean.
Remarks
The default value is True. Set this property to False if you don’t want to be disturbed by prompts and alert messages while a macro is running; any time a message requires a response, Microsoft Excel chooses the default response.
If you set this property to False, Microsoft Excel doesn’t automatically set it back to True when your macro stops running. Your macro should always set the property back to True when it stops running.