title: Simple regex pattern
body: <p>i'm using C# and i'm trying to allow only alphabetical letters and spaces. my expression at the moment is:</p>
  
  <pre><code>string regex = "^[A-Za-z\s]{1,40}$";
  </code></pre>
  
  <p>my IDE says that \s is an "Unrecognized escape sequence"</p>
  
  <p>what am i missing?</p>