private void registerButton_Click(object sender, EventArgs e) { if (portNumberBox.TextLength == 0 || usernameBox.TextLength == 0) { MessageBox.Show("ERROR: Please insert port number and username."); } else { chatClient.setPortNumber(Convert.ToInt32(portNumberBox.Text)); chatClient.registerToServer(usernameBox.Text, portNumberBox.Text); messageBox.AppendText("You were added to the conversation."); } }