function enTeteGD()
{
   if (screen.width <= 640) return 'images/degrade/degradegd640.gif';
   else if (screen.width <= 800) return 'images/degrade/degradegd800.gif';
   else if (screen.width <= 1024) return 'images/degrade/degradegd1024.gif';
   else return 'images/degrade/degradegd1280.gif';
}
function enTeteDG()
{
   if (screen.width <= 640) return 'images/degrade/degradedg640.gif';
   else if (screen.width <= 800) return 'images/degrade/degradedg800.gif';
   else if (screen.width <= 1024) return 'images/degrade/degradedg1024.gif';
   else return 'images/degrade/degradedg1280.gif';
}

var chaine = '<table width="100%" border="0" background="' + enTeteGD() + '">';
chaine += '  <tr>';
chaine += '    <td width="18%">';
chaine += '      <div align="center"><font color="#FF0000" class="titre">CODIS</font></div>';
chaine += '    </td>';
chaine += '    <td width="64%">';
chaine += '      <p>&nbsp;</p>';
chaine += '      <p><span class="soustitre">Editeur de logiciel, Sp&eacute;cialiste iSeries AS400</span></p>';
chaine += '    </td>';
chaine += '    <td width="9%">';
chaine += '      <div align="right"><img src="images/Ibmpart.gif" alt="codis - partenaire ibm"></div>';
chaine += '    </td>';
chaine += '    <td width="9%"><img src="images/ibmcer_50.jpg" height="70" alt="codis - certifié ibm"></td>';
chaine += '  </tr>';
chaine += '  <tr>';
chaine += '    <td colspan="4"><img src="images/traithor.gif" alt="" width="100%" height="1"></td>';
chaine += '  </tr>';
chaine += '</table>';
document.write(chaine);