Help me for 'No such command 'meetme''

My Asterisk Server’s version is
My OS is RedHat Linux Enterprise 4.0.
When I logged in the asterisk console(using CLI), I typed a command ‘meetme list conferences’ to get all the conferences’ list.
But the system responsed me with the message ‘No such command ‘meetme list conferences’ (type ‘help meetme list’ for other possible commands)’.
Then I tried many other commands relative with meetme or conferece, however, all of them did not work.
So I had to post that question on the forum. Please help me. Thanks.

I believe all you need to list active conferences is “meetme” that should return active conferences and users. “meetme list {room num}” will return active user details.

Thanks for your opinions. But all the commands your sent to me didn’t work yet. It looks like that my Asterisk Server doesn’t recognize all the commmands which begin with ‘meetme’.
So I had to wait ohter more possible solutions.
Thank you once more.