>>>Is there a (API?) function to know whether lan is off or on?
>>>Thanx in advance
>>
>>Can you simply check if network drive is available?
>>
>>Say, Check available drives
>
>it is useful, ok, but something to check if the cable is off?

Function InternetOK
Lparameters lcmyFastLoadedSite
#define FLAG_ICC_FORCE_CONNECTION 0x01
If Pcount()=0
  lcmyFastLoadedSite = "192.168.0.131" && Replace with the IP of the server.
EndIf 
DECLARE INTEGER InternetCheckConnection IN wininet STRING lpszUrlSTRING, INTEGER dwFlags, INTEGER dwReserved
Return InternetCheckConnection(lcmyFastLoadedSite,FLAG_ICC_FORCE_CONNECTION,0)=1