function validchamps(champs, nom)
{
	var retour = "";
	if(champs.value == "")
	{
		champs.style.borderWidth = "1";
		champs.style.borderColor = "#FF0000";
		champs.style.borderStyle = "solid";
		retour = "Le champs " + nom + "\n";
	}else{
		champs.style.borderWidth = "1";
		champs.style.borderColor = "#000000";
		champs.style.borderStyle = "solid";
	}
	return retour;
}

function validform()
{
	var retour = true;
	var message = "";

	message  = validchamps(document.formulaire.txtnom, "Nom");
	message += validchamps(document.formulaire.txtmessage, "Message");
	message += validchamps(document.formulaire.txtemail, "E-mail");

	if( message != "")
	{
		retour = false;
		message = "Veuillez remplir les champs : \n\n" + message;
		alert(message);
	}
	return retour;
}