Specifies if the form is multiple-document interface (MDI) compliant.
Object.MDIForm [= lValue]
The settings for the MDIForm property are:
The form will be combined with a parent form when maximized.
(Default) The form is always in a separate window.
Set a form's MDIForm property to True (.T.) if you want the child form to be combined with the parent when maximized, or to False (.F.) if the child window should be retained as a separate window when maximized.