Automatic disable sync offline files, when on Wlan

Hello.
I got this problem with muy offline file configuration running Windows XP SP3.
I configuart to automatic sync offline files when log off or on. Everything is working fine when connected to the network with the cable.
But now my problem, when the laptop has a network conection with the Wlan, ( only connected the to the internet, and not to server) windows trying to sync, but can’t find ( of courese) the server. So when you shut down windows , tehs sync will give a error and stay at this error message.
What iw want is to of , tell windows to not use the wlan connection, or to suppress the error message.
Is ther a way to do this.

Thanks