public boolean equals(Object obj) {
		if (this == obj)
			return true;
		
		if (obj == null || !(obj instanceof Vertrag))
			return false;
	
		Vertrag other = (Vertrag)obj;
	
		if(other.getVertragsnummer() != getVertragsnummer() ||
				!Helper.compareObjects(this.getDatum(), other.getDatum()) ||
				!Helper.compareObjects(this.getOrt(), other.getOrt()))
		{
			return false;
		}
		
		return true;
	}