The out put from "sudo -k" doesn't return any thing.
The output from "sudo -l" returns:

User Greg may run the following commands on this host:
(devuser) NOPASSWD: ALL
(devuser) NOPASSWD: !SHELLS
(devuser) NOPASSWD: !SU
(root) ALL
(root) /bin/ksh, /usr/bin/ksh, /bin/csh, /usr/bin/csh, /bin/sh, /usr/bin/sh, /sbin/sh, /usr/bin/tcsh
(root) !SU
usr/local/apache2/bin/apachectl


Also; i was asking how can user Greg sudo as "devuser" user so when he sudo he becomes "devuser" so he doesn't have to type sudo before every command he needs to run as "devuser", in other word, how can he sudo to become "devuser" to make the prompt changes from:
#Greg@server>
to
#devuser@server>


I hope i'm making it this question clear enough