Whats wrong with this code, im getting blue line under the createStatus next the switch

Error message: Use of unassigned local variable 'createStatus'  MembershipCreateStatus createStatus; MembershipUser newUser = Membership.CreateUser(Username.Text, Password.Text, Email.Text); switch (createStatus) { case MembershipCreateStatus.Success: this.CreateAccountResults.Text = "The user account was successfully created!"; break; case MembershipCreateStatus.DuplicateUserName: this.CreateAccountResults.Text = "There already exists a user with this username."; break; case MembershipCreateStatus.DuplicateEmail: this.CreateAccountResults.Text = "There already exists a user with this email address."; break; ...