Networking :: Hacking WEP Key With Backtrack3

I am new to all this so I don't understand much of the language used in linux or backtrack, but I founded in a forum how to hack wep and I did this steps: I have a IWL 4965 AGN I tried to hack a wireless but I get errors, this is what I did:

1)airmon-ng
wlan0 intel 4965 a/b/g/n iwl 4965 - [phy0]

2)airmon-ng stop wlan0
wlan0 intel 4965 a/b/g/n iwl 4965 - [phy0]
(monitor mode disabled)

3)ifconfig wlan0 down
4)macchanger --mac 00:11:22:33:44:55 wlan0
Current mac: 00:1d:e0:4f:99:4b (unknown)
faked mac: 00:11:22:33:44:55 (cimsys inc)

5)airmon-ng start wlan0
wlan0 intel 4965 a/b/g/n iwl 4965 - [phy0]

ERROR: Neither the sysfs interface links nor the iw command is available.
Please download and install iw from dl.aircrack-ng.org/iw.tar.bz2
So I downloaded this from the Page and tried to install it.

6)cd '/root/iw'
iw# make
CC iw.o
iw.c:11:31: error: netlink/genl/genl.h: No such file or directory
iw.c:12:33: error: netlink/genl/family.h: No such file or directory
iw.c:13:33: error: netlink/genl/ctrl.h: No such file or directory
iw.c:14:25: error: netlink/msg.h: No such file or directory
iw.c:15:26: error: netlink/attr.h: No such file or directory
iw.c: In function 'nl80211_init':
iw.c:25: error: implicit declaration of function 'nl_handle_alloc'
iw.c:25: warning: assignment makes pointer from integer without a cast
iw.c:31: error: implicit declaration of function 'genl_connect'
iw.c:37: error: implicit declaration of function 'genl_ctrl_alloc_cache'
iw.c:37: warning: assignment makes pointer from integer without a cast
iw.c:44: error: implicit declaration of function 'genl_ctrl_search_by_name'
iw.c:44: warning: assignment makes pointer from integer without a cast
iw.c:54: error: implicit declaration of function 'nl_cache_free'
iw.c:56: error: implicit declaration of function 'nl_handle_destroy'
iw.c: In function 'nl80211_cleanup':
iw.c:62: error: implicit declaration of function 'genl_family_put'
make: *** [iw.o] Error 1