2010年9月12日,刘媛与孟方签订房屋租赁合同,约定孟方将小区一处楼房租给刘媛使用3年。双方约定好租金以及租赁期内孟方不得出售等内容,刘媛按时支付了租金。两年后,孟方与王明签订了这套楼房出售合同,并以45万元卖给王明。刘媛得知后,将孟方告到法院,要求法院认定房屋买卖合同无效。 September 12, 2010, Liu Yuan and Meng Fang signed a contract for housing leasing, agreed to Meng Fang district rented a house to Liu Yuan use 3 years. The two sides agreed that the rent should be good, and Meng Fang could not sell during the lease term. Liu Yuan paid the rent on time. Two years later, Bangladesh and Wang Ming signed a contract for the sale of this building and sold for 450,000 yuan to Wang Ming. After Liu Yuan learned that Meng told the court, asking the court found that the sale of housing contracts is invalid.