0
                        
                        
                    You can verify its availability by checking: if (typeof nslider != "undefined" && typeof nslider.getSlides() != "undefined"){...}
Please check out its example in the post: http://www.menucool.com/5871/Specify-the-starting-image-slide-of-image-slider-by-page-URL-query-string
<script type="text/javascript">
    function switchSlide() {
        if (typeof nslider != "undefined" && typeof nslider.getSlides() != "undefined") {
            // It is ready now. You can call the slider's built-in functions
            ......
        }
        else {
            setTimeout(switchSlide, 10);
        }
    }
</script>