Basic AK question

[Xizor]

First of all. Hello to you all, I'm new in this forum so please don't be too harsh on me.
I have been lurking for a couple of weeks and decided I would post a hand for a change:
The hand history is gone for some reason so I'll write it off my memory.

I'm playing Prima 2/4$ full ring four tabling and reading 2+2.

All relevant stacksizes are $400 I don't have a read on the villain in this hand, but I haven't seen him get out of line.

I am dealt A [img]/images/graemlins/heart.gif[/img] K [img]/images/graemlins/diamond.gif[/img]

1 fold, a very good player limps, I raise $16 a guy in MP calls and a guy in LP calls, blinds fold and the limper before me calls.

Flop: A [img]/images/graemlins/spade.gif[/img] 6 [img]/images/graemlins/club.gif[/img] 3 [img]/images/graemlins/club.gif[/img] pot is $70

Checked to me, I bet $45, MP folds, LP clickraises to $90, the early limper folds.

What's my move? What does his raise mean?

Thanks in advance.