static LRESULT DepInfoBoxProc (HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
 struct _DepInfo *info;
 
 switch(message) {
 case MSG_INITDIALOG:
 {
 /* 
 * Get the lParam passed to this dialog box, and assign it
 * to the second private additional data assoiciated
 * with the dialog box.
 */
 info = (struct _DepInfo*)lParam;
 SetWindowAdditionalData2 (hDlg, (DWORD)lParam);
 break;
 }

 case MSG_COMMAND:
 {
 /* 
 * Get the parameter from the second private data assoiciated
 * with the dialog box.
 */
 info = (struct _DepInfo*) GetWindowAdditionalData2 (hDlg);

 switch(wParam) {
 case IDOK:
 /* Use the data in the parameter. */
 ......

 case IDCANCEL:
 EndDialog(hDlg,wParam);
 break;
 }
 }
 }
 
 return DefaultDialogProc (hDlg, message, wParam, lParam);
}