to_anchor.js

$(function(){

    var hashTagActive = "";
        $(".scroll").on("click touchstart" , function (event) {
            if(hashTagActive != this.hash) { //this will prevent if the user click several times the same link to freeze the scroll.
                event.preventDefault();
                //calculate destination place
                var dest = 0;
                if ($(this.hash).offset().top > $(document).height() - $(window).height()) {
                    dest = $(document).height() - $(window).height();
                } else {
                    dest = $(this.hash).offset().top;
                }
                //go to destination
                $('html,body').animate({
                    scrollTop: dest
                }, 2000, 'swing');
                hashTagActive = this.hash;
            }
        });
});