popup.html

<!DOCTYPE html>
<html>
  <head>
      <title>Domain Swap</title>
      <script src="popup.js"></script>
  </head>

  <body>
    <table>
        <tr>
            <td>
                Domain:
            </td>
            <td>
                Swap to Domain:
            </td>
        </tr>
        <tr>
            <td>
                <input placeholder="instagram.com" id="txtSource" />
            </td>
            <td>
                <input placeholder="imginn.com" id="txtDest" />
                <button type="button" id="cmdAdd">Add</button>
            </td>
        </tr>
    </table>
    <br/>
    Swaps:<br/>
    <table>
    	<tr>
    		<td>
    			<select id="swapList"></select>
    		</td>
    		<td>
    			<button type="button" id="cmdDel">Edit/Delete</button>
    		</td>
    	</tr>
    </table>
  </body>
</html>