title: Add/Remove handler to textbox
body: <p>I am adding a handler to textbox using the following code:</p>
  
  <pre><code>private void frmLogin_Load(object sender, EventArgs e)
  {
      foreach (Control tb in this.Controls)
      {
          if (tb is TextBox)
          {
              TextBox tb1 = (TextBox)tb;
              tb1.KeyDown += new KeyEventHandler(TextBox_KeyDown);
          }      
      }
  }
  </code></pre>
  
  <p>I am also removing handler using the following code:</p>
  
  <pre><code>private void frmLogin_FormClosed(object sender, FormClosedEventArgs e)
  {
      foreach (Control tb in this.Controls)
      {
          if (tb is TextBox)
          {
              TextBox tb1 = (TextBox)tb;
              tb1.KeyDown -= new KeyEventHandler(TextBox_KeyDown);
          }
      }
  }
  </code></pre>
  
  <p>Is the correct way or is there a better alternative?</p>