$(document).ready(function() {
	$("[id*=son_]").hide();
	$("[id*=imgson_]").attr('src','./images/menu+.png');
	$("[id*=imgson_]").show();

	$("[id*=menumain_]").toggle(
			function(){ 
				$(this).next().slideDown();
				$(this).find("[id*=imgson_]").attr('src','./images/menu-.png');
			}, function() { 
				$(this).next().slideUp();
				$(this).find("[id*=imgson_]").attr('src','./images/menu+.png');
			});
});