Posting PO invoice voucher

HI ALL

I am trying to insert two more line in invoice voucher where as by standered three lines are inserted

the marked lines are inserted by standered  and the rest lines are inserted by me 
and while posting my lines for the particular account the amount is not posted in General Ledger --> main accounts--> posted

I am inserting value to generaljournalaccountentry table and subledgerjournalaccountentry table

and Please help me to find where through code the vouchers are created while posting PO invoice  

Thanks and Regards

Lishani J