title: Allow backspace button to work in validated TextBox
body: <p>I have the following code to only allow letters in the text box:   </p>
  
  <pre><code>private void TextBox1_KeyPress(object sender, KeyPressEventArgs e)
  {
    Char pressedKey = e.KeyChar;
    if (Char.IsLetter(pressedKey))
   {
  // Allow input.
  e.Handled = false
  }
    else
  e.Handled = true;
  }
  }
  </code></pre>
  
  <p>How can I allow the backspace key to work because, it doesnt let me to delete characters after typed</p>