If Black plays Nxb4 in the Evans Gambit

Hi everyone! I have a question: 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 in this position 4...Bxb4 is the main move but what if Black plays 4...Nxb4?

Thanks but the line that you just told me about with 4...Nxb4 5.c3 Nc6  6.d4. What is the compensation for the lost pawn?

The compensation for the lost Pawn is that while Black has been dicking around with the Bishop between c5, b4 and back to c5, only to move it again on the next move, White has played c2-c3 and d2-d4.

If you can't see why that provides compensation, why are you playing gambits?

@Savage47 Ok, Thanks again

@bleemu I am not an aggressive player but I want to so I asked my coach that how can I become an aggressive player? He replied saying Try some Gambits so I was looking forward to play the Evans Gambit and I asked about the Evans Gambit in this forum as my coach is not knowing any theory about the Evans Gambit since he never plays 1.e4 he always plays 1.d4. When I found out that Nxb4 is also a move in the Evans Gambit I asked about the compensation for the pawn in this forum so this is why I am playing gambits. Thanks for you answer