获取触点坐标总是报错

Creator 2.x
#1

this.node.on(‘touchstart’,function(event){
var target=event.getCurrentTarget();
// 获取点击坐标

        var locationInNode=target.convertToNodeSpace(touches.getLocation());
        console.log(locationInNode);
    })

错误信息：main.js:25 Uncaught ReferenceError: touches is not defined