public ObjectId(){
  _time=(int)(System.currentTimeMillis() / 1000);
  _machine=_genmachine;
  _inc=_nextInc.getAndIncrement();
  _new=true;
}

public ObjectId ( ) { _time = ( int ) ( System . currentTimeMillis ( ) / 1000 ) ; _machine = _genmachine ; _inc = _nextInc . getAndIncrement ( ) ; _new = true ; }
create a new object id .
