private LoginResult UsernameRegistered() { SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString); string selectTxt = "SELECT id FROM users WHERE LOWER(username) LIKE LOWER(@user)"; conn.Open(); SqlCommand cmd = new SqlCommand(selectTxt, conn); cmd.Parameters.Add(new SqlParameter("@user", TypeCode.String)); cmd.Parameters["@user"].Value = Username.Text; SqlDataReader result = cmd.ExecuteReader(); if (!result.Read()) { conn.Close(); return(LoginResult.Unregistered); } result.Close(); selectTxt += " AND password like @pass"; cmd = new SqlCommand(selectTxt, conn); string hashedPassword = AuthenticationUtilities.HashPassword(Password.Text); cmd.Parameters.Add(new SqlParameter("@user", TypeCode.String)); cmd.Parameters.Add(new SqlParameter("@pass", TypeCode.String)); cmd.Parameters["@user"].Value = Username.Text; cmd.Parameters["@pass"].Value = hashedPassword; result = cmd.ExecuteReader(); if (result.Read()) { conn.Close(); return(LoginResult.Success); } conn.Close(); return(LoginResult.WrongPassword); }