How to make the vertical scroll animation stay at N point while scrolling

Question

<script>
    $(function () {
        $('a[href*=#]:not([href=#])').click(function () {
            $(".link").removeClass("active");
            $(this).addClass("active");
            if (location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '') && location.hostname == this.hostname) {
                var target = $(this.hash);
                target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
                if (target.length) {
                    $('html,body').animate({
                        scrollTop: target.offset().top
                    }, 1000);
                    return false;
                }
            }
        });
    });

I have this function to make the vertical div scrollable, how do I implement the function to make it trigger only at certain points?