private void SignUp_User_change(object sender, EventArgs e) //signing up { User user = new User(); user.Username = SignUp_User_txt.Text; if (Transmitter.CheckUser(user))//check if username is Available { SignUp_User_Label.ForeColor = Color.Green; SignUp_User_Label.Text = "OK ✓"; usercheck = true; } else { SignUp_User_Label.ForeColor = Color.Red; SignUp_User_Label.Text = "Username used before"; usercheck = false; } }