I need help on this...

mob
Login()
usr.loc = locate(1,1,1)
team = rand(1,4)
if(team == 1)
team_name = "Red Team"
world << "[usr] has joined the [team_name]'s Alliance!"
if(team == 2)
team_name = "Green Team"
world << "[usr] has joined the [team_name]'s Alliance!"
if(team == 3)
team_name = "Blue Team"
world << "[usr] has joined the [team_name]'s Alliance!"
if(team == 4)
team_name = "Yellow Team"
world << "[usr] has joined the [team_name]'s Alliance!"

I'm getting these errors...
login.dm:4:error:rand:undefined proc
login.dm:5:error::invalid expression

and yes i have a team and team_name var...

Thanx,
Punkrock546