Most Microsoft Forms 2.0 controls in an Microsoft Outlook custom form support only one event, the Click event.
A control bound to a field does not fire the Click event. You must handle the appropriate field event to detect a user's interaction with a control bound to a field.
The following Forms 2.0 controls and Outlook controls fire the Click event whenever a user clicks anywhere in the control.
While the MultiPage control itself does not support the Click event, an individual Page on a MultiPage control will fire the Click event if the user clicks inside the client area of the page, but not if the user clicks the tab associated with the page.
To detect a change in a TextBox control, bind the control to a field and then handle the appropriate field event. If you have to further extend controls in a custom form, customize a form with Outlook controls in a form region instead of Forms 2.0 controls in a form page. For more information, see Controls in a Custom Form.