title: Regex to match numbers and commas, but not numbers starting with 0 unless it's 0,
body: <p>Well I tried to sum it up in the title.</p>
  
  <p>I need a reg ex to match numbers and commas, but not numbers starting with 0 unless it's 0,number</p>
  
  <p>My users enter hours in a field, so they have to be able to enter 0,3 hours, but they are not allowed to write 002 or 09.</p>
  
  <p>I have this reg ex</p>
  
  <pre><code>^[0-9]*\,?[0-9]+$
  </code></pre>
  
  <p>How can I extend it to not allow start with 0 unless the 0 is followed by a comma </p>