var tab_selected = '';
	function tabs(id){
		if(id!=tab_selected){
			if(tab_selected!=''){
				$(tab_selected).className = 'tab_normal';
				Effect.Fade('contenido_' + tab_selected, { duration: 0.1 });
				Effect.Appear('contenido_' + id, { duration: 0.1 });
			}
			$(id).className = 'tab_selected';
			tab_selected = id;
			
		}		
	}