DoubleClick object in Fabric.js

HTML

<script src="https://raw.github.com/kangax/fabric.js/master/dist/all.js"></script>
<canvas id="c" width="400" height="400"></canvas>

CSS

canvas{
  border-width: 1pz;
  border-style: solid;
  border-color: #000;
}

JavaScript

var lastTime;
var src = "http://fabricjs.com/lib/pug.jpg";
// canvas
var canvas = new fabric.Canvas('c');
canvas.observe("object:selected", objectSelectedHandler);
canvas.backgroundColor = "#F5F5F5";

// text
var text = new fabric.Text('Text inside canvas', { 
  left: 200, 
  top: 50 
});
text.hasRotatingPoint = true;
canvas.add(text);

// circle
var circle = new fabric.Circle({
    left: 200,
    top: 150,
    radius: 50,
    fill: "#dd0000"
});
circle.hasRotatingPoint = true;
canvas.add(circle);

//image
fabric.util.loadImage(src, function(img) {
    var object = new fabric.Image(img);
    object.set({ 
        left: 200, 
        top: 300
    });
    object.hasRotatingPoint = true;
    object.scaleX = object.scaleY = .25;
    canvas.add(object);
    canvas.renderAll();    
});

canvas.renderAll();

function objectSelectedHandler(event) {
    var date = new Date();
    var now = date.getTime();
    if(now - lastTime < 500){
        objectDoubleClickHandler(event);
    }
    lastTime = now;
}

function objectDoubleClickHandler(event){
    alert('bm,,m')
}