Each time employees at BizCorp enter their work computers, the following alert appears: "You are attempting to access the BizCorp network. By logging in, you agree to BizCorp's Computer Usage Policy and certify that your use of this computer is strictly for business purposes. Any activities conducted on this system may be monitored for any reason at the discretion of BizCorp" Once an employee has logged in, have the parties formed a valid contract? Discuss.