I am using backtrack 4(but that section of the forum seems to be dead) I'm trying to hack WPA I'm using AWUS036H wireless adapter.
The code I am using is

airodump-ng -c 1 -w  --bssid (their bssid)  mon0

aireplay-ng -0 15 -a  -c  mon0
I send between 59-75 deauths (i.e 67/67) but I never get a handshake no matter how many times I re-do it. Am I too far? Because I am losing alot of data. I did "iwconfig" and my IEEE is b/g but the connection i'm trying to hack is n. Could this be why? If so how do I activate N? Any help would be appreciated.