-extern void ChoiceClassCB(FL_OBJECT *, long);
-extern void DocumentCancelCB(FL_OBJECT *, long);
-extern void DocumentApplyCB(FL_OBJECT *, long);
-extern void DocumentOKCB(FL_OBJECT *, long);
-extern void DocumentDefskipCB(FL_OBJECT *, long);
-extern void DocumentSpacingCB(FL_OBJECT *, long);
-extern void DocumentBulletsCB(FL_OBJECT *, long);
+extern "C" void ChoiceClassCB(FL_OBJECT *, long);
+extern "C" void DocumentCancelCB(FL_OBJECT *, long);
+extern "C" void DocumentApplyCB(FL_OBJECT *, long);
+extern "C" void DocumentOKCB(FL_OBJECT *, long);
+extern "C" void DocumentDefskipCB(FL_OBJECT *, long);
+extern "C" void DocumentSpacingCB(FL_OBJECT *, long);
+extern "C" void DocumentBulletsCB(FL_OBJECT *, long);