In August of 1968 P approached the president of D about an idea Hoffman had for a corner irrigation system. As a result, D arranged to meet with P at the latter's home to discuss the matter. P and his brother-in-law had roughly sketched a drawing of the system, the concept of which P then thought to be original with him, and had the sketch notarized. In essence, the idea involved attaching a swinging arm controlled by a steerable wheel to an irrigation system. According to P, D looked the drawings over and said he thought the idea was a good one. P and D discussed developing the idea and obtaining a patent on it, as well as the employment of P by D. P began working for D. P worked for D until 1973 or 1974, then worked elsewhere for 9 months and returned to D until approximately 1976. The president of D never worked with P to develop the system P had conceived. Believing that D was not going to develop his system, P took his idea to Valmont Industries sometime during the spring of 1971. Valmont, not interested. D became involved in litigation with Valmont. On March 14, 1981, D asked P for his cooperation in the Valmont suit and to make copies of P's original drawings. P did cooperate with D and gave a deposition in connection with the Valmont suit. In April 1981, P discovered that D was selling a corner irrigation system which utilized a swinging arm and steerable wheels. P sued D alleging that D breached an express agreement to develop P's unpatented idea for a corner irrigation system and pay him a royalty thereon, or unjustly enriched itself by appropriating the idea. D answered by denying P's claims and asserting that any cause of action P may have had is time-barred and that the parties abandoned any contractual rights which might have existed. The district court granted D's motion for summary judgment and dismissed P's petition. P appealed.