Simple expect question

[urgrue <urgrue@bulbous.org>]

I'm trying to make a simple script that will do with telnet what one can
do with ssh when you do "ssh hostname command". iow:
telnet somehost command

then it should, using expect (presumably), telnet into somehost, prompt
me interactively for the username/password, and after successfully
logging in run the command specified on somehost.

As simple as that sounds, I can't figure it out. I've gotten this far
which is probably done all wrong:

#!/usr/bin/expect

spawn telnet [lrange $argv 0 0\n]  #telnet to host given on command line
expect { "login:"
	#how to prompt user interactively for input here?
        "password:"
	#how to prompt user interactively for input here?
	#somehow check for successful login here
        send "[lrange $argv 1 99]" #send command-line args to host
        send "exit\r"
}



any help appreciated.