How to mount usb flash disk on FreeBSD 7.0

[Tsetsbold]

Hi all,

I am newbie to UNIX and using FreeBSD 7.0 current ,and I cannot mount my 
USB flash disk. I searched on google but couldn't find anything helpful.

I did this steps.

#mkdir /mnt/usb
#mount /dev/da0 /mnt/usb
mount: /dev/da0 : Invalid argument

# mount -t vfat /dev/da0 /mnt/usb
mount: /dev/da0 : Operation not supported by device

#dmesg
umass0: <USB2.0 Flash Disk, class 0/0, rev 2.00/1.00, addr 2> on uhub6
da0 at umass-sim0 bus 0 target 0 lun 0
da0: <USB2.0 Flash Disk 5.00> Removable Direct Access SCSI-2 device
da0: 40.000MB/s transfers
da0: 2028MB (1038592 2048 byte sectors: 255H 63S/T 64C)
(da0:umass-sim0:0:0:0): SYNCHRONIZE CACHE. CDB: 35 0 0 0 0 0 0 0 0 0
(da0:umass-sim0:0:0:0): NOT READY asc:3a,0
(da0:umass-sim0:0:0:0): Medium not present
(da0:umass-sim0:0:0:0): SYNCHRONIZE CACHE. CDB: 35 0 0 0 0 0 0 0 0 0

Now I really don't know what to do? Can anybody advice me what to do?

Thanks,
Tsetsbold