title: Add string to end of URL in iframe tag
body: <p>I have a URL in my iFrame:</p>
  
  <p><code>&lt;iframe src="http://example.com/video/123/"&gt;&lt;/iframe&gt;</code>.</p>
  
  <p>In PHP, how do I edit this to add <code>?wmode=transparent</code> to the end of the URL.</p>
  
  <p>Thank you</p>