uses Wininet,windows;
var
  flags: DWORD;
begin
 InternetGetConnectedState(@flags,0);
 if (flags and INTERNET_CONNECTION_LAN) = INTERNET_CONNECTION_LAN then MessageBoxA(0,'LAN Connection','lan',0);
end.

 if GetSystemMetrics(SM_NETWORK) and $01 = $01 then  MessageBoxA(0,'LAN Connection','lan',0);