every time i use airodump-ng it gives me an error

error :

ioctl(SIOCSIWMODE) failed:
Device or resource busy

ARP linktype is set to 1 (Ethernet) - expected ARPHRD_IEEE80211,
ARPHRD_IEEE80211_FULL
or ARPHRD_IEEE80211_PRISM instead.
Make
sure RFMON is enabled: run 'airmon-ng start wlan0 <#>'
Sysfs injection support was not found either.

i know the card is supported and that it works

when i type in ifconfig it says that encap is configure to ethernet


sorry for bad english and iam new to backtrack