The WinCreateHelpInstance() function returns a window handle. This is the handle of the application's main help window. The main help window is created by IPF, with a standard format and with a window procedure supplied by Presentation Manager. Whenever a help panel is displayed, it appears as a child window of the main help window.
The main help window has a title bar, which contains a title specified by the application. The application passes this title in the pszHelpWindowTitle parameter to the WinCreateHelpInstance() function.
The main help window contains a menu bar with several pulldown menus allowing the user to perform text searches, view the index, etc. An application developer may modify this menu bar using the resource definitions contained in the hmtailor.rc file provided with IPF. This file includes an hmtailor.h file, which contains the integer constant definitions for the menu bar and pulldown menu items. Additional items may be defined within the help pulldown menu, but their resource identifiers should be between 7F00 and 7FFF to avoid conflicts with identifiers already defined.
When the menu bar of the main help window has been modified, it must be resource-compiled in the normal way, and combined with the application's executable file or with a DLL. Its resource identifier must then be specified in the idActionBar parameter of the WinCreateHelpInstance() function call. If additional accelerator keys have been defined, the identifier of the accelerator table must also be defined in the idAccelTable parameter.
If the menu bar and accelerator table definitions have been combined with a DLL, the module handle of this DLL must be specified in the hmodAccellActionBarModule parameter. The module handle must first be obtained using the DosLoadModule() or DosGetModuleHandle() functions. These functions are described in Loading Resources From a DLL.