How to use deluid?

[iSee]

I use gpg --edit-key to delete a deluid like this:

-x- Begin -x-
[isee at snail .gnupg]$ gpg --edit-key yu xin 
gpg (GnuPG) 0.9.2; Copyright (C) 1999 Free Software Foundation, Inc.
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions. See the file COPYING for details.

Secret key is available.

pub  1024D/79184EC1  created: 1998-12-30 expires: never      trust: -/u
sub  1024g/AB2D5D38  created: 1998-12-30 expires: never
(1)  Yu Xin (iSee) <isee at 126.com>
(2)  Yu Xin (iSee) <isee at i.am>
(3)  Yu Xin (iSee) <mere at heidi.isee.online.sh.cn>
(4)  Yu Xin (iSee) <yuxin at i.am>

Command> deluid <isee at i.am>
You must select at least one user id.

Command> deluid Yu Xin (iSee) <isee at i.am>
You must select at least one user id.    

Command> deluid 2
You must select at least one user id.

Command> quit  
-x- End -x-

I want to know how to deluid?

Yu Xin