title: Digit Grouping in .NET
body: <p>How do we input digit grouping in C#? My code works but only for one instance. I have to constantly click it to group every number in the calculator. How do we do group it so that if we click it, it groups every number (not only the number presented), and if we uncheck the checkbox, it doesn't?</p>
  
  <p>This is the current code:</p>
  
  <pre><code>NumberFormatInfo nFI = new CultureInfo("en-US", false).NumberFormat;
  
  
  double int_value = Convert.ToDouble(textboxt1.text);
  
  
  textbox1.Text = int_Value.ToString("N", nFI);
  </code></pre>