This java script exception you will get if your browser less than IE 8 version. Because JSON.stringify not part of the IE 7 and lower versions.
To resolve this issues you need to add the reference of Crockford's JSON2
Download the JSON 2 script file from following website https://github.com/douglascrockford/JSON-js
Add reference to your web page. Run the application now you will not get the JSON undefined error
Happy coding …..