var menuInterval;
var originalMenu = null;
var subMenuSet = false;

Event.observe(window, "load", function() {
  var subMenus = $$('#sub_nav ul');
  var main = $$('ul#main_nav li');
  var b = $$('body')[0];
  
  b.classNames().each(function(className) { 
	var s = "nav-" + className;
  	if ($(s) != null && originalMenu == null)
	{
		originalMenu = $(s);
	}
  });

  main.each(function(item) {
	item.observe('mouseover', 
		function(evt)
		{
			subMenus.each(function(subItem){
				subItem.hide();
				});
			
			var el = Event.element(evt);
			var sel = "#sub_nav ul#nav-" + el.id;
			var subnav = $$(sel);

			if (subnav && subnav.length>0) 
				subnav[0].setStyle({display: 'block'});
				subMenuSet = true;
			});
    });
  
  Event.observe(document, "mousemove", function(evt) {
		if (subMenuSet && 
			!Position.within($('sub_nav_box'), evt.pointerX(), evt.pointerY())
			&& !Position.within($('main_nav_box'), evt.pointerX(), evt.pointerY())
			)
		{
			subMenuSet = false;
			$$('#sub_nav ul').each(function(subItem){
				subItem.hide();
				});									
			if (originalMenu != null)	
				originalMenu.show();	
		}
  });
  
});