title: How to insert a thousand separator (comma) with convert to double
body: <p>I am trying to format the contents of a text box:</p>
  
  <pre><code>this.lblSearchResults1.Text =
      Convert.ToDouble(lblSearchResults1.Text).ToString(); 
  </code></pre>
  
  <p>How do I amend this so that I the text includes comma/thousand separators?</p>
  
  <p>i.e. 1,000 instead of 1000.</p>