function triggerTouch(eventName, mouseEv) {
        var touchEvent = document.createEvent('Event');
        touchEvent.initEvent(eventName, true, true);

        touchEvent.altKey = mouseEv.altKey;
        touchEvent.ctrlKey = mouseEv.ctrlKey;
        touchEvent.metaKey = mouseEv.metaKey;
        touchEvent.shiftKey = mouseEv.shiftKey;

        touchEvent.touches = getActiveTouches(mouseEv, eventName);
        touchEvent.targetTouches = getActiveTouches(mouseEv, eventName);
        touchEvent.changedTouches = getChangedTouches(mouseEv, eventName);

        eventTarget.dispatchEvent(touchEvent);
    }
trigger a touch event
@param eventName
@param mouseEv