vertical-enable.iscroll.js

var point, pointStartX, pointStartY, deltaX, deltaY, isHorizontal;
var scroller = new iScroll('scrollerId', {
    vScroll: false,
    vScrollbar: false,
    hScrollbar: false,
    snap: 'li',
    momentum: false,
    onBeforeScrollStart: function(e) {
        point = e.touches[0];
        pointStartX = point.pageX;
        pointStartY = point.pageY;
        deltaX = Math.abs(point.pageX - pointStartX);
        deltaY = Math.abs(point.pageY - pointStartY);
        if(deltaX >= deltaY){ isHorizontal = true; }
    },
    onBeforeScrollMove: function(e) {
        if (isHorizontal) { e.preventDefault(); }
    }
});