<script>
    (function () {
        var docElem = window.document.documentElement,
            didScroll, scrollPosition;

        // trick to prevent scrolling when opening/closing button
        function noScrollFn() {
            window.scrollTo(scrollPosition ? scrollPosition.x : 0, scrollPosition ? scrollPosition.y : 0);
        }

        function noScroll() {
            window.removeEventListener('scroll', scrollHandler);
            window.addEventListener('scroll', noScrollFn);
        }

        function scrollFn() {
            window.addEventListener('scroll', scrollHandler);
        }

        function canScroll() {
            window.removeEventListener('scroll', noScrollFn);
            scrollFn();
        }

        function scrollHandler() {
            if (!didScroll) {
                didScroll = true;
                setTimeout(function () {
                    scrollPage();
                }, 60);
            }
        };

        function scrollPage() {
            scrollPosition = {
                x: window.pageXOffset || docElem.scrollLeft,
                y: window.pageYOffset || docElem.scrollTop
            };
            didScroll = false;
        };

        scrollFn();

        [].slice.call(document.querySelectorAll('.morph-button')).forEach(function (bttn) {
            new UIMorphingButton(bttn, {
                closeEl: '.icon-close',
                onBeforeOpen: function () {
                    // don't allow to scroll
                    noScroll();
                },
                onAfterOpen: function () {
                    // can scroll again
                    canScroll();
                },
                onBeforeClose: function () {
                    // don't allow to scroll
                    noScroll();
                },
                onAfterClose: function () {
                    // can scroll again
                    canScroll();
                }
            });
        });

        // for demo purposes only
        [].slice.call(document.querySelectorAll('form button')).forEach(function (bttn) {
            bttn.addEventListener('click', function (ev) {
                ev.preventDefault();
            });
        });
    })();
</script>