2. The owner of real estate may accept, rely upon, and enforce an unconditional waiver of lien, voluntarily executed by another who furnished materials for the construction of improvements on the same premises, where such owner, in good faith, relying upon such waiver, has paid the contract price in full. Kiowa Lumber Co. v. Oklahoma City Building Loan Association et al., 168 Okla. 540, 34 P.2d 592. By the pleadings the evidence complained of became material, and there was no error in receiving same.