rem: (*ePtr->deleteProc) (ePtr->arg, ePtr->id);
add: (*ePtr->deleteProc) (ePtr->arg, (int)ePtr->id);
context: FreeEvent(Event *ePtr){    if (ePtr->deleteProc != NULL) {	(*ePtr->deleteProc) (ePtr->arg, ePtr->id);    }    ns_free(ePtr);}