AT_ERRCOUNT ACCUAPI IG_GUI_page_file_append(
        HWND hwndPage, 
        const LPSTR lpcszFileName
);

HIGEAR hIGear;    /* HIGEAR handle of image */
HWND hWnd, hWndPage;    /* Windows handles */
AT_ERRCOUNT  nErrCount; /* tally of IG errors on the stack */
UINT nCurrentPage; /* number of page currently active */
case ID_FILE_OPENDOCUMENT:
        if (GetOpenImageFileName(hWnd, szFile, sizeof(szFile)))
        {
        SetCursor(LoadCursor(NULL, IDC_WAIT));
        /* create the page sorter window, if it does not already exist*/
                if (!IsWindow(hwndPage))
                {
                nErrCount = IG_GUI_page_window_create(hWnd, IG_GRP_DEFAULT, 
                "Page Window", CW_USEDEFAULT, 
                CW_USEDEFAULT, 320, 200, &hwndPage);
                /* attach select, delete and order callbacks */
                IG_GUI_page_order_CB_register(hwndPage, 
                PageOrderProc, NULL);
                IG_GUI_page_select_CB_register(hwndPage, 
                PageSelectProc, NULL);
                IG_GUI_page_delete_CB_register(hwndPage, 
                PageDeleteProc, NULL);
                nCurrentPage = 0;
                }
                /* now add the full document to the page window */
                nErrCount = IG_GUI_page_file_append(hwndPage, szFile);
                /* set the initial page */
                if (!nCurrentPage)
                {
                nCurrentPage = 1;
                /* set the active page */
                IG_GUI_page_active_set(hwndPage, nCurrentPage);
                }
                else
                {
                /* get the new page */
                IG_GUI_page_active_get(hwndPage, &nCurrentPage);
                IG_GUI_page_handle_get(hwndPage, nCurrentPage, &hIGear);
                }
                /* change the title of the main window to reflect a filename 
                        change */
                wsprintf(szBuf, "%s Page:  %d", (LPVOID)szFile, nCurrentPage);
                SetWindowText(hWndMain, szBuf);
                /* tell windows to tell us to paint the new image */
                InvalidateRect(hWnd, NULL, FALSE);
                UpdateWindow(hWnd);
                SetCursor(LoadCursor(NULL, IDC_ARROW));
        }
break;