$(function(){
	$("#navigation a").hover(function(){
		valeurs = $(this).attr("class").split("_");
		$("#navigation_over").css("background-image","url("+ chemin_commun +"images/tuiles/navig_" + valeurs[1] + "_over.gif)");
	},function(){
		$("#navigation_over").css("background-image","none");
	});
});