The form of contract under discussion contains as its next paragraph, "The seller agrees that................brought about this sale and agrees to pay the broker's commission therefore. This provision is entirely unnecessary to the validity of the contract. Its omission does not even affect the broker's claim for commission. He becomes entitled to his commission as soon as he has brought about the agreement. The only object gained by its insertion in the contract is as a specific declaration by the parties that the broker brought about the sale.