title: Convert letter from textBox to an integer
body: <p>How do I convert alphabet letter from <code>textBox</code> to an integer? </p>
  
  <p>For example, if the user inputs <code>"B"</code> in the <code>textBox</code>, I am trying to convert <code>B</code> to the number <code>1</code></p>
  
  <pre><code>string a = textBox1.Text
  int number = 1;
  
  number = int.Parsed (a);
  
  messageBox.Show(number.ToString());
  </code></pre>