// Prevent Drag in Wechat
    var overscroll = function(el) {
        el.addEventListener('touchstart', function() {
            var top = el.scrollTop,
                totalScroll = el.scrollHeight,
                currentScroll = top + el.offsetHeight;
            //If we're at the top or the bottom of the containers
            //scroll, push up or down one pixel.
            //
            //this prevents the scroll from "passing through" to
            //the body.
            if (top === 0) {
                el.scrollTop = 1;
            } else if (currentScroll === totalScroll) {
                el.scrollTop = top - 1;
            }
        });
        el.addEventListener('touchmove', function(evt) {
            //if the content is actually scrollable, i.e. the content is long enough
            //that scrolling can occur
            if (el.offsetHeight < el.scrollHeight)
                evt._isScroller = true;
        });
    }
    overscroll(document.querySelector('.swiper-container'));
    document.addEventListener('touchmove', function(evt) {
        //In this case, the default behavior is scrolling the body, which
        //would result in an overflow.  Since we don't want that, we preventDefault.
        if (!evt._isScroller) {
            evt.preventDefault();
        }
    });