if there is a raise in front of me and i have AK .. normally i'll just call and see what develops on the flop. if you reraise preflop with AK against AA KK or QQ your going to get reraised again.. calling with just AK, you have a shot at out drawing AA KK with a straight or flush if its suited, or perhaps out draw the KK with an ace on the flop. just dont move all in or call in with AK i see this mistake a ton at the tables.

AA or KK its an automatic reraise.