[Tutor] Problem to recognize string

[W X Liu]

Hi all,

I am writing a piece of program to interact with telnet, here is the program

import telnetlib
import sys 


a=telnetlib.Telnet(host='mudlib.anarres.org',port='5000')
a.read_until('Anarres II login:')
b=str('acb'+chr(5))
a.write(b+ "\n")
b=str('y'+chr(2))
a.write(b+ "\n")
b=str('spam hi'+chr(15))
a.write(b+ "\n")
if a.read_until('hi'):
   b=str('spam hello')
   a.write(b+ "\n")

print a.read_all()

The question is that I want to wait for somebody to say 'hi' to this program 
instead of program itself. So it cannot recognize who said 'hi', everytime I 
run it, it will print doubly the 'hi', in fact I want this progran say hi and 
somebody replies it with saying 'hi', then program  say hello.

So anyone can help me to solve this problem? 

Wenxin