addSubMenu = function(){
	$('#sub_menu').append('<li><a href="generalinfo.html">About the Exhibition</a></li><li><a href="visitorsbook.html">Visitors Book</a></li>');
	// selects the active menu
	var path = location.pathname.substring(1);
	var indx = path.lastIndexOf('/');
	var pagename = path.slice(indx+1);
   if ( path )
     $('#sub_menu a[@href$="' + pagename + '"]').attr('class', 'current-item');
}
$(document).ready(function(){
  	addSubMenu();
});