I think this means you don't have the en_US locale installed on your machine. I tried that same command on a Solaris 9 12/02 machine and got the same error. Try this (p.s. I'm doing this under ksh):
export LANG=en_US.ISO8859-1
This locale should work fine for you. You may even consider using the en_US.UTF-8 locale. The only comment I have about UTF-8 is it causes my Netscape 7 to act REALLY weird under fluxbox. UTF-8 also makes the xterm windows include a language selection frame box at the bottom of the each xterm window. This is what I think makes Netscape 7 a bit whacky for me. Using en_US.ISO8859-1, Netscape 7 works just fine.
Thenk you! I had found this problem. It's a fixed line in packages. I can not modified it. So, I had to install language packages. :-(
root@>locale -a
POSIX
common
en_US.UTF-8
C
iso_8859_1
th
th_TH
th_TH.TIS620
chinese
zh
zh_CN.EUC
zh.GBK
zh_CN.GBK
zh.UTF-8
zh_CN.UTF-8
zh_TW
zh_TW.EUC
zh_TW.BIG5
zh_TW.UTF-8
de