public boolean objectCanNew (ObjectContainer container) throws Db4oException {
		if(this.customer == null) throw new Db4oException("Customer cannot be null!");
		if(this.startDate == null) throw new Db4oException("Start date cannot be null!");
		if(this.startKm != null)
			if(this.startKm < 0) throw new Db4oException("Start KM cannot be smaller 0!");
		if(this.endKm != null)
			if(this.endKm < 0) throw new Db4oException("End KM cannot be smaller 0!");
		if(this.vehicle == null) throw new Db4oException("Vehicle cannot be null!");

		return true;
	}