var menus = new Array("subnav-1", "subnav-2", "subnav-3", "subnav-4");
var menu_states = new Array(0, 0, 0);

$(document).ready(function () {
	$("div.nav_main ul li").hover(
		function() { 
			var class_over = $(this).children('ul').attr('class');
			if (class_over != null) {
				var i_over = find_index(class_over);
				if (i_over > -1) {
					menu_states[i_over] = 1;	
				}
			}
		},
		function() {
			var class_out = $(this).children('ul').attr('class');
			if (class_out != null) {
				var i_out = find_index(class_out);
				if (i_out > -1) {
					menu_states[i_out] = 0;	
				}
			}
		}
	);

	setInterval(menu_update, 250);
});

function find_index(className) {
	for(var i=0; i<menus.length; i++) {
		if (className == menus[i])
			return i;
	}
	return -1;
}

function menu_update() {
	for (var i=0; i<menu_states.length; i++) {
		if (menu_states[i] == 1) {
			$("ul." + menus[i]).slideDown();
		} else {
			$("ul." + menus[i]).slideUp();
		}
	}
}