function setUpExpandoNav() {
    // Put a clickable icon at the end of any item that should be expandable.
    $("li.en_flag").append("<span>[+]</span>");
    $("li.en_flag2").append("<span class=\"active\">[-]</span>");

    // Allow only three visible levels at once.  i.e. Remove the expando icon <span> from the third level.
    $("li.expandonav li.expandonav li.expandonav")
        .removeClass("expandonav")
        .removeClass("en_flag")
        .removeClass("en_flag2")
        .children().filter("span").remove();

    // Click handler for expando icon.
    $("li.en_flag>span,li.en_flag2>span").click(
        function() {
            // If this expando item does NOT already have data filled in...
            var associatedUls = $(this).siblings().filter("div").children();
            if (associatedUls.length == 0)
            {
                $(this).addClass("loading");
                var navUrl = $(this).siblings().filter("a").attr("href").replace(/\s+$/,"");
                if (navUrl.startsWith("http"))
                {
                    var idx = navUrl.indexOf("/", 8);
                    navUrl = navUrl.substring(idx);
                }
                var thisId = $(this).parent().attr("id");
                var targetId = thisId + "_items";
                var ajaxUrl = "/_layouts/ccf/NavData.aspx?url=" + navUrl + "&navId=" + thisId;
                $(this).parent().append("<div style='display:none;' id='" + targetId + "'/>");
                $("#"+targetId).load(ajaxUrl, "", function() {
                    setUpExpandoNav();

                    // Inside this load() finished handler "this" is the newly added <div>
                    $(this).siblings().filter("span").removeClass("loading");

                    // The new <UL> will be display:none by default.  Slide it open.
                    $(this).css("display", "block");
                    $(this).children().slideDown("fast", function() {
                        // Inside this handler, "this" is the animated <ul>
                        $(this).parent().siblings().filter("span").addClass("active");  // Make the <span> "active".
                    });

                });   // end of load() finished handler

            }
            else    // Sub items already downloaded... either hide or show.
            {
                // associatedUls is a wrapped set.
                if (associatedUls.css("display") == "none")
                {
                    associatedUls.parent().css("display", "block");  // Show the DIV before showing the UL.
                    associatedUls.slideDown("fast",  function() {
                        // Inside this handler, "this" is the animated <ul>
                        $(this).parent().siblings().filter("span").addClass("active");
                    });
                }
                else
                {
                    associatedUls.slideUp("fast",  function() {
                        // Inside this handler, "this" is the animated <ul>
                        $(this).parent().css("display", "none");  // Done hiding the UL, hide the DIV.
                        $(this).parent().siblings().filter("span").removeClass("active");
                    });
                }
                //associatedUls.slideToggle("fast",  function() {
                //    // Inside this handler, "this" is the animated <ul>
                //    $(this).parent().siblings().filter("span").toggleClass("active");
                //});
            }
        }      // end of span click() handler
    )
    .hover(
        function() {
            $(this).addClass("hover");
        },  // end of span hoverover handler
        function() {
            $(this).removeClass("hover");
        }   // end of span hoverout handler
    )
    .parent().removeClass("en_flag").removeClass("en_flag2");
}

$(document).ready(function() { setUpExpandoNav(); });