function afficher_lexique(lettre) {
	//var alphabet = ["a","b","c","d","e","f","m","n","o","p","r","s","t","u","v"];
	var alphabet = ["a","b","c","d","e","f","m","n","o","p","r","s","t"];
	for(var i=0;i<alphabet.length;i++) {
		//Effect.SlideUp(alphabet[i]);
		$(alphabet[i]).style.display = "none";
	}
	Effect.SlideDown(lettre);
	//$(lettre).style.display = "block";
}