NA or none??

[minup_123]

Hi all
While going thru US consulate website I read that we shud write "None" (Site says we cant use -NA-)for all the questions which are non applicable in visa forms.But while filling the form its mandatory to use "NA" where the question is not applicable.If we try using None its giving an error.Can anyone help me with this??
Refer this link for more info

http://chennai.usconsulate.gov/required_documents.html

Thanks
Minu

[immihelp]

If it is really NA, go ahead and write NA, irrespective of what instructions say what.