def post(self):
     self.response.headers['Content-Type'] = 'application/json'
     jsonString = self.request.body       
     data = simplejson.loads(jsonString)
     contract = RentalContract()
     contract.createRentalContract(data)
     payment = Payment()
     payment.initializePayment(contract)
     #.createCheckinActivityRecord()          
     checkinResponse = {'checkinSuccessMessage':'Congratulations, you have checked in the room successfully!'}
     jsonCheckinResponse = simplejson.dumps(checkinResponse)
     return self.response.out.write(jsonCheckinResponse)