Installing Backtrack to USB

[purehate]

Backtrack 4 USB Install - Offensive Security

[james2088]

（Problem has been resolved）what i used is DELL notebook,and 4GB DIESEL USB. I'am new. step by step, i'am flowing the video,but now i have something wrong, i don't know how to go on? here is:

Disk /dev/sda1: 4009 MB, 4009722368 bytes
124 heads, 62 sectors/track, 1018 cylinders
Units = cylinders of 7688 * 512 = 3936256 bytes
Disk identifier: 0x27a63f09

Device Boot Start End Blocks Id System
/dev/sda1p1 * 1 401 1541413 b W95 FAT32
/dev/sda1p2 402 802 1541444 83 Linux


root@bt:~# mkfs.vfat -F 32 -n BT4 /dev/sda1p1
mkfs.vfat 2.11 (12 Mar 2005)
/dev/sda1p1: No such file or directory
root@bt:~# mkfs.ext3 -b 4096 -L casper-rw /dev/sda1p2
mke2fs 1.41.3 (12-Oct-2008)
Could not stat /dev/sda1p2 --- No such file or directory

The device apparently does not exist; did you specify it correctly?
root@bt:~#

And here is the photo snapshot1.jpg, h t t p ://sites.google.com/site/redstorey12/news/snapshot1.jpg
anyone can help me?