function insertarPie() 
{ 
tabla='<table width="100%" border="0" cellspacing="0" cellpadding="0">'+
  '<tr> '+
  '  <td width="100%"> '+
  '    <div align="center"></div>'+
  '  </td>'+
  '</tr>'+
  '<tr> '+
  '  <td width="100%">'+
  '    <div align="center"><font face="Arial, Helvetica, sans-serif" size="2">Copyright '+
  '      © 2004 Serdeypo S.L.L All rights reserved</font> </div>'+
  '  </td>'+
  '</tr>'+
'</table>';
document.write(tabla); 
}