jquery.SPServices CAML query no working on Nintex form

I trying to call a jquery.SPServices CAML query, It work on normal Sharepoint form, but fail on Nintex Form.

This is what have i done on the Nintex form,

Add the JavaScript reference library to the Custom JavaScript Includes (under form settings)

https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js 

https://mySharepointSite/SiteAssets/jquery.SPServices-0.7.2.min.js
https://mySharepointSite/SiteAssets/SupplierRegister_OpenAccount.js

https://mySharepointSite/SiteAssets/SupplierRegister_OpenAccount.js

 Where executing, on line 12, its always return "parserror".

Please help. Thank you.

Further drill down. I found this on the response message.

I believe its because the Nintex Form Iframe cause this problem.......