Who is connected to a server using Remote Desktop (command line command)

I was trying to connect to a machine, and then I get 'terminal server connection exceeded...' notification.
I was wondering if there is a way to find out who is connected to the machine so that i can send an email who is in 'Disconnected' mode or something.
I took the help of a network administrator, and he gave me one simple command that I ran from command line and it gave me the list of all sessions connected/disconnected to the machine.
Here you go:
C:\>qwinsta /server:urservername [press enter]

If you want to remove any instance/session, then run the following:
C:\>rwinsta /server:urservername ID# [press enter]

I like to mention it here though.