></script>
<script type='text/javascript' src='//metanit.com/js/jquery.treeview.min.js'></script>
<script type='text/javascript' src='//metanit.com/js/syntax12.js'></script>
<script type='text/javascript'>SyntaxHighlighter.all();</script>
<script>
$(function() { 
	$("#menuButton").on('click', function(){
          $(this).toggleClass('menu-opened');
          var mainmenu = $('.mainmenu');
          if (mainmenu.hasClass('open')) { 
            mainmenu.removeClass('open');
          }
          else {
    