function InternetExist: Boolean;
var TCP:TIdTCPClient;
begin
Result := False;TCP:=TIdTCPClient.Create(nil);
TCP.Host:='google.com';
TCP.Port:=80;
TCP.ReadTimeout:=2000;
try TCP.Connect;
Result:=TCP.Connected;
TCP.Free;
except
Result:=False;TCP.Free;
end;
end;