Screen Resolution

[Paulo Alfredo Mainieri Junior]

Dears Programmers:

I'm looking for a function capable to return the screen resolution that
is been used. I found a function called "OSScreenResolution" in
OSKERNEL.DCL, in the OsIO directory. I tried to use it but fail every
time. This is my program test:

module test
import oskernel
Start = OSScreenResolution 0


and the message error is: 

	"error L2029: 'OSScreenResolution' : unresolved external"

What does that mean? How can I use it? Is that the correct function to
be used?
My CLEAN is an OS/2 version. I used the compilation option: 

			"clm -p -sl -d test"

I'm very thankful for help.

Paulo.