移動端touch事件

var startX = startY = endX = endY = 0;  
        var dom = document.getElementById('main');
        //touchStart事件
        dom.addEventListener('touchstart',function(event){
            var touch = event.targetTouches[0];
            startX = touch.pageX;
            startY = touch.pageY;
            document.getElementById('start').value = startX + '，' + startY;
        },false);
        //touchmove事件
        dom.addEventListener('touchmove',function(event){
            var touch = event.targetTouches[0];
            endX = touch.pageX;
            endY = touch.pageY;
        },false);
        //touchend事件
        dom.addEventListener('touchend',function(event){
            document.getElementById('end').value = endX + '，' + endY;
            document.getElementById('count').value = (endX - startX) + '，' + (endY - startY);
        },false);