function checkform ( form )
{

  if (form.nom.value == "") {
    alert( "Be careful : Name" );    
    return false ;
  }
  if (form.prenom.value == "") {
    alert( "Be careful : Firstname" );    
    return false ;
  }
  if (form.adresse.value == "") {
    alert( "Be careful : Address" );    
    return false ;
  }
  if (form.code.value == "") {
    alert( "Be careful : Zip code" );    
    return false ;
  }
  if (form.ville.value == "") {
    alert( "Be careful : City" );    
    return false ;
  }
  if (form.pays.value == "") {
    alert( "Be careful : Country" );    
    return false ;
  }
  if (form.telephone.value == "") {
    alert( "Be careful : Phone" );    
    return false ;
  }
  if (form.key.value == "") {
    alert( "Be careful : Code to copy" );    
    return false ;
  }
  
  var reggy = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
  if ((form.email.value != "") && (!reggy.test(form.email.value))) { alert("Be careful : Email"); return false; }
  
  if (form.cgv.checked == false) {
    alert( "Be careful : case à cocher" );    
    return false ;
  }

  return true ;
}