How to change dictionary in Indesign by Apple Scripting

Hi Friends,

I am new to Indesign Scripting through Apple Script.

I was trying to work on a script which can basically change my default setting of dictionary in Indesign to "English: USA" when we go to Indesign---> Preferences---> Dictionary

I was trying the below code in AppleScript.

tell application "Adobe InDesign CS4"

          tell document preferences of dictionary

                    set language name of document preferences to "English: USA"

          end tell

end tell

However, it is showing error.

Would appreciate if you can guide and suggest the correct way.

Also, in character styling (please see below screen-shot) I need to change my dictionary to "English: USA". Please suggest if this is possible to achieve by AppleScript.

Thanks for your help and suggestion!

Regards,

Abhishek