The user will have to validate (or fill the code you gave) via Edit Profile - Additional Information ?

Yes, user will fill the additional fields in "About me" tab and click save (ajax save).....my plugin gets triggered at user_presavedata hook. which means (correct me if I am wrong) that when user enters the value and clicks save, my plugin executes first before saving the value in the database.
My plugin then validates that the entered information is consistent (i.e the API call) and then I change user's usergroup and the value is saved in the profile field.....

I would rather create a custom page where your users can validate, add a new database table with codes inserted than using the method which you are trying to do.

I would not be going for new database as the code is unique for every user and I validate it via a 3rd party call, so I am not aware of the codes the user is having...
Anyways, I believe that I am not doing this right:
as soon as I pass the contents of json everything works fine...

So tell me, what your 'some API URL' is?

~~ url removed ~~

just a sample...

--------------- Added [DATE]1355339588[/DATE] at [TIME]1355339588[/TIME] ---------------

I found a js error which appears when someone tries to change the profile field.
http://www.imagetoo.com/images/screentxt.png

--------------- Added [DATE]1355340181[/DATE] at [TIME]1355340181[/TIME] ---------------

I tried with Curl also but no luck....any clues how/why am I getting this js error on profile field save?
Here's my forum link (in case you want to try):
http://forums.vibethemes.com

--------------- Added [DATE]1355341379[/DATE] at [TIME]1355341379[/TIME] ---------------

Update: API call works, validate working, some issue with json handling....working on it..

--------------- Added [DATE]1355370916[/DATE] at [TIME]1355370916[/TIME] ---------------

Finally got it working!!

Cheers!
( v )
http://forums.vibethemes.com