function ChoixCSS() {
  if ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) < 6 ))
    {
       if (navigator.vendor=="")
         { //mozilla
           css="styles/onglet.css";
         }
       else
         {
           css="styles/onglet_n.css";
         }
    }
  else
    {css="styles/onglet.css";} 
  document.write("<LINK rel='StyleSheet' type='text/css' href='"+css+"'>");
}