service Tax

Dear Buddies,

i have question to ask from u all People.

here is a case .

There is one party from which we pur  as well as make sales to them.on both transaction Service tax is apllicable.

now can i adjust ouput & input service against them.

i mean we make make after ajdusting .

for example

sales come to rs 3 cr

purchase come to 3.10 cr

only balance to pay  .10 cr

to can i can iput credit on above .10 cr to pay.