Menu not displaying on node-webkit

Everyone!
I was working on a small project and i came across to this situation. One of my friend suggested me of using menu. I used following code as sample.

    <script>
    var gui = require('nw.gui'), db = require('diskdb'), fs = require("fs"), path = require('path');
    var win = gui.Window.get();     
    var menu = new gui.Menu();
    var info_item = new gui.MenuItem({ label: 'Which Fruit Do I Love?' });
    menu.append(info_item);
    menu.popup(500, 20);        
    var process = false, scr = 0, directory, w, h, ratio,canvas, base_, files_   = new Array(), files = new Array();
    db = db.connect("lib/collections", ['libery', 'temp']);
    .
    .
    </script>

It worked.And I thought lets try other way. So I added a little code at the bottom. But as soon as I changed code to this:

<script src="js/jquery.min.js"></script>
<script>
    var gui = require('nw.gui'), db = require('diskdb'), fs = require("fs"), path = require('path');
    var win = gui.Window.get();     
    var menu = new gui.Menu();
    var info_item = new gui.MenuItem({ label: 'Which Fruit Do I Love?' });
    menu.append(info_item);     
    var process = false, scr = 0, directory, w, h, ratio,canvas, base_, files_   = new Array(), files = new Array();
    db = db.connect("lib/collections", ['libery', 'temp'])
    $('body').on('contextmenu', function(ev) { 
        ev.preventDefault();
        menu.popup(ev.x, ev.y);
        return false;
    });
</script>

Then I got error saying following:

Uncaught node.js Error

TypeError: undefined is not a function
at Menu.popup (menu.js:69:6)
at HTMLBodyElement.<anonymous> (file:///E:/projects/desktop%20app/lib/protype.html:138:10)
at HTMLBodyElement.x.event.dispatch (file:///E:/projects/desktop%20app/lib/js/jquery.min.js:5:9843)
at HTMLBodyElement.y.handle (file:///E:/projects/desktop%20app/lib/js/jquery.min.js:5:6633)

Then later i kept everything same and just moved of line of code below like this:

  <script>
    ....
    ....
    var process = false, scr = 0, directory, w, h, ratio,canvas, base_, files_   = new Array(), files = new Array();
    db = db.connect("lib/collections", ['libery', 'temp']);    
    var menu = new gui.Menu();
    var info_item = new gui.MenuItem({ label: 'Which Fruit Do I Love?' });
    menu.append(info_item);    
    $('body').on('contextmenu', function(ev) { ...
    ....
  </script>

And now amazing thing is it again gave error as bellow:

Uncaught node.js Error##

TypeError: undefined is not a function
at new Menu (menu.js:32:6) at file:///E:/projects/desktop%20app/lib/protype.html:134:14

I dont get it. Whats wrong with my code? I don't understand why does it says error. I have read the menu docs and I think there isn't anything wrong with my code. If there is then please do help me. And If anyone can please explain win in earth I am getting these error. Thank you.