title: How to modify custom fields meta box in WordPress
body: <p>In WordPress, when editing a post or a page, the Custom Field meta box allows the user to enter a name (meta_key) and a value (meta_value). I'm trying to modify the meta box so that the user can enter a:</p>
  <blockquote>
  <p>a) name</p>
  <p>b) value 1</p>
  <p>c) value 2</p>
  </blockquote>
  <p>My aim is to then use <code>get_post_meta()</code> to do something like this on the front-end of the site:</p>
  <pre><code>&lt;a href=&quot;&lt;?php echo $value1; ?&gt;&quot;&gt;
      &lt;img src=&quot;&lt;?php echo $value2; ?&gt;&quot; alt=&quot;&quot; /&gt;
  &lt;/a&gt;
  </code></pre>
  <p><strong>My question:</strong> How can I modify the Custom Fields meta box so that the user is able to enter 2 values next to each name?</p>
  <p>So far, I've tried to use <a href="http://codex.wordpress.org/Function_Reference/add_meta_box" rel="nofollow noreferrer">add_meta_box()</a> but this adds a <em>new</em> box. My problem is I need to modify the existing box.</p>