jQuery code to detect the HTML content of the button and grow or shrink the popup navigation container

btnPopup

<script type="text/javascript">
    $(document).ready(function () {
        $("#btnPopup").click(function () {
            var div = $("#popup-nav-content");
            var btn = $("#btnPopup");
            var btnHTML = btn.html();

            if (btnHTML == "Show Nav") {
                btn.html("Hide Nav");
                div.css("display", "block");
                div.animate({ height: '300px' }, "slow");
            }

            else
            {
                btn.html("Show Nav");
                div.animate({ height: '0px' }, "slow");
            }
            
        });
    });
</script>