JQuery getJSON Problem

I am trying to get a sample app running, that will read a local json file for testing.  I have the latest rhoelements runtime running fine, the script is firing on a button press.

 

The file test.json is { "ABC" : "123" } and it is in the rootfolder for the device (a mc9190g). ( have tried it in various subfolders - with slashes).

 

$.getJSON('test.json',  function(data) { alert('HELLO');} );

 

-- I would expect this to at least fire the alert box with the word HELLO in it.

 

Jscript after this works fine, and I am using jquery to update values - so I know that is loading fine.

 

IS getJSON not supported or is there something fundamental I am missing? (like I can't read from the local file system?)

 

Thanks.