                     </button>
                   </td>
                 </tr>
-              </table>    
+              </table>
 
               <div>
               <h2>Constants</h2>

                  <li>R<sub>E</sub>: Radius of the Earth = 6,371 km</li>
                  <li>M<sub>E</sub>: Mass of the Earth = 5.97 x 10<sup>24</sup> kg</li>
                  <li>AU: Astronomical Units. 1AU is the distance from the earth to the sun. 1AU = 149,598,000 km</li>
                </ul>  
              </div>
              
              <p>Many thanks to the author of the original <a href="http://www.kianjin.com/pcalc.html">Planetary Calculator</a> for allowing us to produce a second simpler version. For a more details about how this calculator works, please visit the original <a href="http://www.kianjin.com/pcalc.html">site</a>.</p> 
          '''

  # INITIAL TUTORIAL

                </tr>
                <tr>
                  <td><span id="radP"></span></td>
                  <td><span id="volP"></span></td>
                  <td><span id="massP"></span></td>
                  <td><span id="rhoP"></span></td>
                </tr>
                <tr>
                  <th colspan="2">Time taken for the exo-planet to transit it's star.</th>
                  <th>Distance of exo-planet from it's star.</th>
                  <th>Temperature</th>
                </tr>
                <tr>
                  <td colspan="2"><span id="tdur"></span></td>
                  <td><span id="distP"></span></td>
                  <td><span id="tempP"></span></td>
