document.observe('dom:loaded', function() { 
	
	var nav = $('parent-nav-services');
	var subnav = $('subnav-services');
	
  nav.observe('mouseenter', function(event) {  
  	nav.addClassName('active');
    subnav.show();
  });	
      
  nav.observe('mouseleave', function(event) { 
  	nav.removeClassName('active'); 
    subnav.hide();
  });	   
 
});