public void FillListAdmin()
        {
            try
            {
                string UserNameForChecking
                     = HttpContext.Current.User.Identity.Name; /* For checking admin permission. */
                conn = new SqlConnection("server=10.100.100.25\\SPLAHOST;Database=graphs;Integrated Security=false;User ID=petpakn;Password=net123321!;");
                conn.Open();
                // Create SqlCommand to select pwd field from users table given supplied userName.
                cmd = new SqlCommand("Select uname from Users", conn); /// Intepolation or the F string. C# > 5.0
                // Execute command and fetch pwd field into lookupPassword string.
                SqlDataReader sdr = cmd.ExecuteReader();
                while (sdr.Read())
                {
                    admins.Add(sdr["uname"].ToString());
                }
                listAdmin.DataSource = admins;
                listAdmin.DataBind();
                ConnectionStringSettingsCollection connections = ConfigurationManager.ConnectionStrings;

                conn = new SqlConnection("server=10.100.100.25\\SPLAHOST;Database=graphs;Integrated Security=false;User ID=petpakn;Password=net123321!;");
                conn.Open();
                // Create SqlCommand to select pwd field from users table given supplied userName.
                cmd = new SqlCommand("select company_name from companies ", conn); /// Intepolation or the F string. C# > 5.0
                // Execute command and fetch pwd field into lookupPassword string.
                SqlDataReader reader = cmd.ExecuteReader();
                while (reader.Read())
                {
                    strings.Add(reader["company_name"].ToString());
                }

                ConnectionStrings.DataSource = strings;
                ConnectionStrings.DataBind();
                // unit test

                cmd.Dispose();
                conn.Close();
            }
            catch (Exception ex)
            {
                // Implement logging here.
            }
        }