title: append string to src
body: <p>I need to append a sting of text "&amp;showinfo=0" to the end of an iframe src attribute.</p>
  
  <p>I have tried</p>
  
  <pre><code>document.getElementsByTagName('iframe').src += "&amp;showinfo=0";
  </code></pre>
  
  <p>but no luck</p>