It is agreed that the contract does not create rights or obligations except for contractual asset year, a so-called relativity effect of the contract in terms of people, and spends Banasrav provisions of the contract to the limbs, or be in their judgment, Valacod not harm or benefit only Aakadiha. If this general principle governing the effects of the contract in the light of the provisions of the law and the limits of freedom of contractors in terms of the legal texts make pacta contractors commit themselves to implement it without departing from its provisions, and where the contractors are free to limit the effects of the contract between them; the latter fact is the work of voluntary, the realization of their will may require, that does not exceed its effects to others. However, this principle is sometimes not an obstacle to the possibility of the contract to a third party. Just have a role in the will of the infinite effects of the contract between the parties, it has to allow others to take advantage of some of its effects. If the law had been counted that these effects do not harm not only the contracting parties stating it sometimes arranges for other rights arising out of it and therefore it was necessary for the legislature that no grounds logical, realistic been or philosophical, justifying its intervention and allow the flow of rights over others.