Example 

i have multi pal income account Income Account One and Income Account Two 

and i have one product A

by default what do do ... when i sale product A Product Sales Account hit for Income .....

case is i have condition  if product sale to Mr A then Account hit Income Account one 

if sale Mr B then Account hit Income Account Two 
else hit Product Sale Account 
can you please guide me where i can modify which method need to update where i can pass my account_id.id as pr my condition?