uses 
 WinInet; 

const 
 MODEM = 1; 
 LAN = 2; 
 PROXY = 4; 
 BUSY = 8; 

function GetConnectionKind(var strKind: string): Boolean; 
var 
 flags: DWORD; 
begin 
 strKind := ''; 
 Result := InternetGetConnectedState(@flags, 0); 
 if Result then 
 begin 
 if (flags and MODEM) = MODEM then strKind := 'Modem'; 
 if (flags and LAN) = LAN then strKind := 'LAN'; 
 if (flags and PROXY) = PROXY then strKind := 'Proxy'; 
 if (flags and BUSY) = BUSY then strKind := 'Modem Busy'; 
 end; 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
var 
 strKind: string; 
begin 
 if GetConnectionKind(strKind) then 
 ShowMessage(strKind); 
end;