$(function() {
	$("#subnavi1,#subnavi2,#subnavi3,#subnavi4,#subnavi5,#subnavi6").css("display","none");

	$("#navi a").hover(function() {
		var Image_pass = $(this).css("backgroundImage").split(".jpg");
		$(this).css("backgroundImage",Image_pass[0] + "_on.jpg" + Image_pass[1]);
	},
	function() {
		var Image_pass2 = $(this).css("backgroundImage").split("_on.jpg");
		$(this).css("backgroundImage",Image_pass2[0] + ".jpg" + Image_pass2[1]);
	});
});