Self opening box

var servo = require("servo").connect(B1);

var sensor = require("HC-SR04").connect(A6,A5,function(dist) {

var open = false;
servo.move(1);

 if (dist > 5 && dist < 20) {
   console.log("open ("+Math.round(dist)+")");
   servo.move(0);
 } else {
   console.log("close ("+Math.round(dist)+")");
 servo.move(1);
 }
});
setInterval(function() {
 sensor.trigger();
}, 2000);