title: regex for money values in JavaScript
body: <p>Been out of the <code>regex</code> game for a while. Trying to come up with something that will allow the user to enter a money value either with/without dollar sign or with/without commas. For example, all the of the following values should be valid:</p>
  
  <pre><code>5
  5.1
  5.10
  $5
  500,000
  500,000.1
  500,000.10
  $100,000,000.50
  etc....
  </code></pre>
  
  <p>Could someone please help me out?</p>