title: extract text between string - javascript
body: <p>I have a string: </p>
  
  <pre>&lt;iframe src="keep-url" width="125" height="290" frameborder="0" scrolling="no"&gt;&lt;/iframe&gt;</pre>
  
  <p>I want to remove all except:</p>
  
  <pre>keep-url</pre>
  
  <p>and using Javascript, jquery, with jsfiddle<br/>
  Thank you.</p>