cWindowName

Specifies a window name. If the mouse pointer is positioned over the specified window, MWINDOW(В ) returns true (.T.); otherwise, MWINDOW(В ) returns false (.F.).

Character, Logical

If you omit the optional window name, MWINDOW(В ) returns the name of the window over which the mouse pointer is positioned, or an empty string if the mouse pointer is positioned over the main Visual FoxPro window or over any other window that is not part of Visual FoxPro.