Newbie: problem with own module

[Matthias Stern]

Hi! I have problems building my own modules. This is the a short version 
of the program with all functions (i show here only one) in one file:

---
import WS

def init(name):
    	:
	WS.SetRunMode(1)
    	:

 :
 :

def main():
	init(something)
main()
---

Now I want to put all the functions like "init()" except main() into a 
module. this look like:

module "boo.py":

---
def init(name):
    	:
	WS.SetRunMode(1)
    	:
---

main program:

---

import WS
import boo

def main():
	boo.init(something)
main()
---

When I try to run this IDLE reports:

  File "<snip>\boo.py", line 12, in init
    WS.SetRunMode(1)
NameError: global name 'WS' is not defined


I tried to set a "import WS" command into file boo.py, too. But it didn't 
help. What am I doing wrong?

Thx, Mac