AK line check please

[deflY]

Full Tilt Poker, $0.10/$0.25 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

BB: $65.25
UTG: $38.85
CO: $32.65
BTN: $24.10
Hero (SB): $25.35

Pre-Flop: K[img]/images/graemlins/heart.gif[/img] A[img]/images/graemlins/heart.gif[/img] dealt to Hero (SB)
2 folds, <font color="red">BTN raises to $0.85</font>, <font color="red">Hero raises to $2.80</font>, BB folds, BTN calls $1.95

Flop: ($5.85) K[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] 8[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $4.20</font>, BTN calls $4.20

Turn: ($14.25) 8[img]/images/graemlins/heart.gif[/img] (2 Players)
Hero checks, BTN checks

River: ($14.25) 7[img]/images/graemlins/club.gif[/img] (2 Players)
Hero ? checks/bets(how much?)/ c/RAI?

Villain is 21/8/0,33 (23). What about my turn play?