This message is sent when
|low-order part||The identity of the menu item, accelerator or control window.|
|high-order part||If the message is from a menu, this value is 1. If the message is from an accelerator this value is 0. If the message is from a control window, this part contains the notification code.|
For control windows, this parameter holds a handle of the control window.
If a window processes this message, it should return zero.
accelerator keystrokes matching items from the system menu are translated into system command messages. all other accelerator keystrokes are translated into this message.
If an accelerator keystroke is generated from a minimized window and it matches a menu item mnemonic, no message is generated. If the accelerator keystroke matches no menu item or system menu item, this message is generated despite the window being minimized.