What should I do if a person is wanting me to bribe him?

I have gotten approved a product from a Private company’s head of approvals and after that the Accounts office should give me the purchase order… The accounts guy is, I think very corrupt, may be I’m wrong but it seems so… This man has negotiated a rate after a whole set of meetings, a rate which suits him. I have signed the quotation and now he is delaying the purchase order continuously. He says ‘Sir, I’ll give it to you early next week’ then, another week passed, he said, ‘Oh yes! Don’t worry I will let you know myself as soon as it happens’ then, another week, ‘he says early next week’ and when the early next week comes he says, ‘it is now in the final stages, next week confirmed’ and so on (he’s delaying). My friends say that this guy is certainly wanting me to bribe him and I should bribe him to get my Purchase Order. If I go to the head of approvals, I might get the order but he won’t be very friendly in the years to come and will keep a grudge against me (he’s in an important position) so everyone says I should bribe him because it is essential. I don’t want to, but nothing moves forward without it.

I don’t want to bribe but that guy might not do anything without a bribe. What should I do?