Calculos den javascript

[goizgoiz]

Lo que tengo hasta ahora es simple pero no me sale:

Os pongo el codigo a ver que pasa: no es php eh?

Código PHP:

  <form action="" method="post" name="Myform" id="Myform"> 
                                        <table width="99%" border="0" cellspacing="0" cellpadding="3"> 
                                          <tr> 
                                            <td width="11%" align="left">&nbsp;</td> 
                                            <td width="35%" align="left">Factor geogr&aacute;fico:</td> 
                                            <td colspan="2" align="left" valign="middle" class="texto"><table width="81%" border="0" cellspacing="3" cellpadding="0"> 
                                                <tr> 
                                                  <td><input name="factor" type="radio" value="1"> 
                                                    1</td> 
                                                  <td><input name="factor" type="radio" value="2"> 
                                                    2</td> 
                                                  <td><input name="factor" type="radio" value="3"> 
                                                    3</td> 
                                                  <td><input name="factor" type="radio" value="4"> 
                                                    4</td> 
                                                  <td><input name="factor" type="radio" value="5"> 
                                                    5</td> 
                                                </tr> 
                                            </table></td> 
                                          </tr> 
                                          <tr> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left">Superficie de la estancia: </td> 
                                            <td width="39%" align="left"><input name="superficie" type="text" class="texto" id="superficie"> 
                                              m2</td> 
                                            <td width="15%" colspan="-3" rowspan="2" align="left">&nbsp;</td> 
                                          </tr> 
                                          <tr> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left">Tipo de estancia: </td> 
                                            <td align="left"><table width="60%" border="0" cellspacing="3" cellpadding="0"> 
                                                <tr> 
                                                  <td width="30%"><input name="estancia" type="radio" value="salon"></td> 
                                                  <td width="70%">Sal&oacute;n</td> 
                                                </tr> 
                                                <tr> 
                                                  <td><input name="estancia" type="radio" value="dormitorio"></td> 
                                                  <td>Dormitorio</td> 
                                                </tr> 
                                                <tr> 
                                                  <td><input name="estancia" type="radio" value="cocina"></td> 
                                                  <td>Cocina</td> 
                                                </tr> 
                                                <tr> 
                                                  <td><input name="estancia" type="radio" value="ba&ntilde;o"></td> 
                                                  <td>Ba&ntilde;o</td> 
                                                </tr> 
                                                <tr> 
                                                  <td><input name="estancia" type="radio" value="pasillo"></td> 
                                                  <td>Pasillo</td> 
                                                </tr> 
                                            </table></td> 
                                          </tr> 
                                          <tr> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left">&nbsp;</td> 
                                            <td colspan="-3" align="left">&nbsp;</td> 
                                          </tr> 
                                          <tr> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left">&nbsp;</td> 
                                            <td align="left"><input name="resultado" type="text" id="resultado"></td> 
                                            <td colspan="-3" align="left"><input type="submit" name="Submit" value="Calcular" onClick="sumar()"></td> 
                                          </tr> 
                                        </table> 
                                                                            </form>  
   

Bueno pues gracias