C#

foreach (Control ctrl in this.Controls)
            {
                if (ctrl is RichTextBox)
                {
                    ctrl.KeyPress +=new KeyPressEventHandler(textChanged);
                }
            }

private void textChanged(object sender, KeyPressEventArgs e)
        {
            MessageBox.Show(string.Format("You Pressed {0}", e.KeyChar));
        }

public partial class Form1 : Form
{
	public Form1()
	{
		InitializeComponent();

		foreach (Control control in this.Controls)
		{
			TextBox textBox = control as TextBox;
			if (textBox != null) textBox.KeyPress += new KeyPressEventHandler(textBox_KeyPress);
		}
	}

	void textBox_KeyPress(object sender, KeyPressEventArgs e)
	{
		TextBox textBox = sender as TextBox;
		//Implement logic here
	}

}

EventHandler <PSSaleWS.GetAgencyListCompletedEventArgs>

public delegate void GetAgencyListCompletedEventHandler(object sender, PSSaleWS.GetAgencyListCompletedEventArgs Completed);

ProntoWS.GetAgencyListCompleted += new GetAgencyListCompletedEventHandler(Proxy_AgencyInfoCompleted);

ProntoWS.GetAgencyListCompleted += Proxy_AgencyInfoCompleted;

ProntoWS.GetAgencyListCompleted += new GetAgencyListCompletedEventHandler(Proxy_AgencyInfoCompleted);

// after the following statement I should able to fire up Proxy_AgencyInfoCompleted

GetAgencyList = GetAgencyList = ProntoWS.GetAgencyList(Agent, User, Password, GetCityName, "TR");

private void tb_GotFocus(object sender, System.EventArgs e) {
    TextBox tb=sender as TextBox;  // will be null if sender wasn't a TextBox
    if (tb!=null) tb.BackColor = Color.White;
}

private void HandleLostFocus(object sender, EventArgs e)
{
  TextBox control = sender as TextBox;
  if (control == null) return;
  control.BackColor = Color.LightSteelBlue;
}