ID:143642
 
Code:
var
list
logged
mob
Login()
logged+="[src.key]<br>"
world << output("[logged]","default.who")
Logout()
logged-="[src.key]<br>"
world << output("[logged]","default.who")


Problem description:

runtime error: type mismatch: "Revojake
Jinzounin
" -= "Jinzounin
"
proc name: Logout (/mob/Logout)
source file: sounds.dm,9
usr: Jinzounin (/mob)
src: Jinzounin (/mob)
call stack:
Jinzounin (/mob): Logout()

That happens when he logs out.
var
list
Players = list()

mob
Login()
Players.Add(src.key)
..()

Logout()
Players.Remove(src.key)
del(src)
..()

verb
Who()
for(var/I in Players)
world << I


Look up lists.

More specifically. You didn't declare your list properly.