ios10兼容问题

var lastTouchEnd = 0;

		document.addEventListener('touchend', function(event) {

			var now = (new Date()).getTime();

			if(now - lastTouchEnd <= 300) {

				event.preventDefault();

			}

			lastTouchEnd = now;

		}, false)
//ios10以上兼容性禁止网页缩放