/*阻止用户双击使屏幕上滑*/
var agent = navigator.userAgent.toLowerCase();        //检测是否是ios
var iLastTouch = null;                                //缓存上一次tap的时间
if (agent.indexOf('iphone') >= 0 || agent.indexOf('ipad') >= 0)
{
    document.body.addEventListener('touchend', function(event)
    {
        var iNow = new Date()
            .getTime();
        iLastTouch = iLastTouch || iNow + 1 /** 第一次时将iLastTouch设为当前时间+1 */ ;
        var delta = iNow - iLastTouch;
        if (delta < 500 && delta > 0)
        {
            event.preventDefault();
            return false;
        }
        iLastTouch = iNow;
    }, false);
}