NL100 - Are we calling this river??

[WC3V]

Villain is awful - Just got to the table but seems to be playing most hands.

What is the line on the river here?


Full Tilt Poker, $0.50/$1 NL Hold'em Cash Game, 5 Players
LeggoPoker Hand History Converter

CO: $40
BTN: $66
SB: $40
BB: $59
Hero (UTG): $146.40

CO posts $1
Pre-Flop: J[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] dealt to Hero (UTG)
BB folds, <font color="red">Hero raises to $4</font>, CO folds, BTN calls $4, SB folds

Flop: ($10) J[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/spade.gif[/img] 7[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">Hero bets $7</font>, BTN calls $7

Turn: ($24) K[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $18</font>, BTN calls $18

River: ($60) 8[img]/images/graemlins/heart.gif[/img] (2 Players)
Hero checks, <font color="red">BTN bets $37 and is All-In</font>, Hero ?????