title: change the src of an iframe using javascript
body: <pre><code>&lt;table&gt;
    &lt;tr&gt;
      &lt;td&gt;one&lt;/td&gt;
      &lt;td&gt;two&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
      &lt;td&gt;three&lt;/td&gt;
      &lt;td&gt;four&lt;/td&gt;
    &lt;/tr&gt;
  &lt;/table&gt;
  
  &lt;div id="numbers"&gt;
    &lt;iframe name="letters" src=""&gt;
    &lt;/iframe&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I'd like to have the ability to click on any cell in the table, grab the value inside, show the <code>div</code> and append the <code>iframe src</code> based on the cell's value. When the user clicks on the cell again the <code>iframe</code> becomes blank and the <code>div</code> is hidden.</p>
  
  <p>For example: click cell <code>one</code>, show the <code>div</code> with the <code>iframe src="/one.html"</code>. Click it again, hide the div with a blank <code>iframe</code>.</p>
  
  <p>Thanks in advance!</p>
  
  <p>(Please, no jQuery answers.)</p>