This function returns the handle to the outer frame window or the inner dialog frame window of a secondary window, depending on the handle supplied as input.

Secondary windows utilize two frame windows: a standard frame and a dialog window to implement the sizing and scrolling features. The window handle returned from WinLoadSecondaryWindow is the handle to the standard frame. The window handle passed to the message procedure specified in WinLoadSecondaryWindow is the dialog window handle.

The standard frame window handle must be used when associating a help instance and to do WinSetWindowPos operations.

The dialog window handle should be used as the owner for message boxes and to access the controls on the dialog with WinWindowFromID.

To modify the title bar or the system menu, the application must specify the standard frame window and not the dialog window.