Uncaught TypeError: Cannot read property 'localStorage' of undefined

When I changed localstorage to backend services, I got this error :

Uncaught TypeError: Cannot read property 'localStorage' of undefined

so I commented the reference of localStorage, then it did work.

<!-- script src="http://cdnjs.cloudflare.com/ajax/libs/backbone-localstorage.js/1.0/backbone.localStorage-min.js" type="text/javascript"></script> -->