title: substring/regex to get a src value held in a string
body: <p>I have a string with the value:</p>
  
  <pre><code>var string = "&lt;img alt='' src='http://api.com/images/UID' /&gt;&lt;br/&gt;Some plain text&lt;br/&gt;&lt;a href='http://www.google.com'&gt;http://www.google.com&lt;/a&gt;"
  </code></pre>
  
  <p>I'd like to take the <code>URL</code> held in the <code>src</code> attribute part of the string if possible. </p>
  
  <p>How can I do this using JavaScript?</p>