Project Costing/Billing Implementation

Dear Frns,

I have 4 yrs support exp in Project Costing/Billing, now i would like to learn implementation.

Hence on a test instance i am implementing Fremont Corp as per the project implementation guide.

I have created new legal entity,accounting flxflds ,ledger, business grp and orgsnization using GL and HR responsibilities and created GL,HR,PA and AR responsibilities and assigned MO: Operating Unit,MO:Security Profile,HR:Business Grp and GL:Ledger Name proile options for these responsibililties.

I am stuck on the implementation options billing tab where i have to select the source as project invoices but the same is not avalable and when i try to create it in AR it looks these are many other setups required.