Loading a New Viewer Instance

The Animate command on the Viewer menu actually creates a new instance of Viewer and loads a new copy of the title in the new instance. This part of MENUDEMO resembles the part that displays a given topic, but there is a noticeable difference in the usCommand parameter, as shown in the following code fragment:

case IDM_MVANIM:
    CheckLoadUsa(hwnd) ;
    lstrcpy(Topic,"az_population");
    wsprintf(str, (LPSTR)JITemplate, (LPSTR)BookPath,
             (LPSTR)Topic);
    MVAPI(hwnd, BookPath, cmdMacro | cmdNewInstance,
          (DWORD)(LPSTR)str);
    return 0 ;

Here, the constants cmdMacro and cmdNewInstance are binary-ORed to indicate that the Viewer command should be carried out after MVAPI creates a new instance of Viewer.