Can I get away playing top pair this way?

[sx3_turbo]

Party Poker 0.5/1 Hold'em (9 handed)

Preflop: Hero is Button with A[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG folds, UTG+1 calls, MP1 calls, MP2 calls, MP3 folds, CO calls, <font color="CC3333">Hero raises</font>, SB calls, BB calls, UTG+1 calls, MP1 calls, MP2 calls, CO calls.

Flop: (14 SB) J[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/spade.gif[/img] <font color="blue">(7 players)</font>
SB checks, BB checks, UTG+1 checks, MP1 checks, MP2 checks, <font color="CC3333">CO bets</font>, <font color="CC3333">Hero raises</font>, SB calls, BB folds, UTG+1 folds, MP1 calls, MP2 folds, CO calls.

Turn: (11 BB) K[img]/images/graemlins/diamond.gif[/img] <font color="blue">(4 players)</font>
SB checks, <font color="CC3333">MP1 bets</font>, CO calls, <font color="CC3333">Hero raises</font>, SB folds, MP1 calls, CO calls.

River: (17 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">MP1 bets</font>, CO folds, Hero calls.

Final Pot: 19 BB

Should I have raised the flop? raised the river? Also, what would you pin on MP1?