urgent need for Free Goods configuration

Hi,

i need a document which have steps to configure free goods.

i created a condition record using VBN3 using condition NA00 but free goods doesn't come.

Requirement is

Customer buys 10 items whose item catg is TAN and 1 item is free. so cust pays only for 9 items.

free good is not coming as sub item. i got stuck. please help .

anybody plz send document which have steps to configure.

my email id is afsar2k@gmail.com

Thanks

Afsar