P leased to D under a covenant that the lessee agreed not to assign the lease without the consent of the lessor in writing. D noticed P that it would vacate the premises on a certain date but would help P find a subtenant for the remaining term of D's lease. D offered to P that the U.S. Post Office would rent the property for about $300 per month less. P advised D that they would not consent to the proposed sublease but would require D to pay all remaining rents in full. P sued D and got a summary judgment for $20,656.63. D appealed.