-extern void FaxSendCB(FL_OBJECT *, long);
-extern void FaxCancelCB(FL_OBJECT *, long);
-extern void FaxApplyCB(FL_OBJECT *, long);
-extern void FaxOpenPhonebookCB(FL_OBJECT *, long);
-extern void cb_add_phoneno(FL_OBJECT *, long);
-extern void cb_delete_phoneno(FL_OBJECT *, long);
-extern void cb_save_phoneno(FL_OBJECT *, long);
+extern "C" void FaxSendCB(FL_OBJECT *, long);
+extern "C" void FaxCancelCB(FL_OBJECT *, long);
+extern "C" void FaxApplyCB(FL_OBJECT *, long);
+extern "C" void FaxOpenPhonebookCB(FL_OBJECT *, long);
+extern "C" void cb_add_phoneno(FL_OBJECT *, long);
+extern "C" void cb_delete_phoneno(FL_OBJECT *, long);
+extern "C" void cb_save_phoneno(FL_OBJECT *, long);