$.sidebarmenu = function(menu) {
  var animationspeed = 300;
  
  $(menu).on('click', 'li a', function(e) {
    var $this = $(this);
    var checkelement = $this.next();

    if (checkelement.is('.treeview-menu') && checkelement.is(':visible')) {
      checkelement.slideup(animationspeed, function() {
        checkelement.removeclass('menu-open');
      });
      checkelement.parent("li").removeclass("active");
    }

    //if the menu is not visible
    else if ((checkelement.is('.treeview-menu')) && (!checkelement.is(':visible'))) {
      //get the parent menu
      var parent = $this.parents('ul').first();
      //close all open menus within the parent
      var ul = parent.find('ul:visible').slideup(animationspeed);
      //remove the menu-open class from the parent
      ul.removeclass('menu-open');
      //get the parent li
      var parent_li = $this.parent("li");

      //open the target menu and add the menu-open class
      checkelement.slidedown(animationspeed, function() {
        //add the class active to the parent li
        checkelement.addclass('menu-open');
        parent.find('li.active').removeclass('active');
        parent_li.addclass('active');
      });
    }
    //if this isn't a link, prevent the page from being redirected
    if (checkelement.is('.treeview-menu')) {
      e.preventdefault();
    }
  });
}