//this is the method for authenticating a user
        protected void uxAuthenticate_Click(object sender, EventArgs e)
        {
            //run the authenticate method to see if user already exists
            //First and Last names come from the text boxes
            var customerExists = MarinaManager.Authenticate(uxFirstname.Text, uxLastname.Text);

            if (customerExists == null)           //if the customer does not exist
            {
                var newCust = new Customer        //create a new customer object entity class
                {
                    FirstName = uxFirstname.Text, //add info from text boxes to object
                    LastName  = uxLastname.Text,
                    Phone     = uxPhone.Text,
                    City      = uxCity.Text
                };

                MarinaManager.AddCust(newCust); //call the add method to insert in customer


                Session.Add("CustomerID", newCust.ID);//add id to the session from the object id

                //if logged in successfull, direct to slips page with username Fullname

                var FullName = $"{newCust.FirstName} {newCust.LastName}";

                FormsAuthentication.RedirectFromLoginPage(FullName, false);
            }
            else
            {
                //if the customer does exist, the add id to the session
                Session.Add("CustomerID", customerExists.ID);

                //if logged in successfull, direct to main page with username Fullname
                FormsAuthentication.RedirectFromLoginPage(customerExists.FullName, false);
            }
        }