function Validation()
{
  // Validation du nom
  //Longeur_Nom = document.form.nom.value.length;
 
// Validation du mail
  arobas = document.form.email.value.indexOf("@")
  point = document.form.email.value.indexOf(".", arobas)
  lastpoint = document.form.email.value.lastIndexOf(".")
  if ((arobas<1) || (point<arobas+2) ||
       ((lastpoint!=document.form.email.value.length-4) && (lastpoint!=document.form.email.value.length-3))
      )
  { alert("Email incorrect !");
    return false;
  }
  return true;
}