The decisions have also held that a broker is entitled to a commission whenever negotiations conducted by him on behalf of the principal culminate in the purchase of the property by the principal or would have so culminated but for the principal's interference. See Hill Moultrie v. Wheeler, 2 Ga. App. 349 ( 58 S.E. 502) (1907); Arnold v. Jowers, 102 Ga. App. 29 ( 115 S.E.2d 623) (1960). It is undisputed in this case that neither Smith nor Doubleday participated in any of the negotiations regarding the purchase of the Monroe Drive property.