CO just sat down...

Party Poker
No Limit Holdem Ring game
Blinds: $0.25/$0.50
10 players
Converter

Stack sizes:
UTG: $52.10
Hero: $48.85
UTG+2: $29.12
MP1: $16.20
MP2: $49.85
MP3: $66.05
CO: $50
Button: $52.35
SB: $48.25
BB: $45.35

Pre-flop: (10 players) Hero is UTG+1 with
UTG folds, Hero raises to $2, 4 folds, CO calls $1.5, 3 folds.

Flop: ($4.75, 2 players)
Hero bets $4, CO raises to $11, Hero ????