function init(gr_id){
		var stretchers = $$('div.menu_content'); 
		var togglers = $$('div.display'); 
		var myAccordion = new Fx.Accordion(togglers, stretchers, { opacity: true, alwaysHide: true,
		 transition: Fx.Transitions.quadOut, show:gr_id, duration: 400,
			
			onActive: function(toggler, stretcher){
			document.getElementById('group-'+toggler.id).style.backgroundPosition = '-456px 0';
			},
		
			onBackground: function(toggler, stretcher){
			document.getElementById('group-'+toggler.id).style.backgroundPosition = '0 0';
			}
		});
		document.getElementById('mainmenu').style.visibility = 'visible';
	}