uses ..., Winsock;

function GetLocalIP : string;
type TaPInAddr = array [ 0 .. 10 ] of PInAddr;
     PaPInAddr = ^TaPInAddr;
var  phe  : PHostEnt;
     pptr : PaPInAddr;
     Buffer : array [ 0 .. 63 ] of char;
     I    : Integer;
     GInitData      : TWSADATA;
begin
    WSAStartup($ 101 , GInitData);
    Result := '';
    GetHostName(Buffer, SizeOf(Buffer));
    phe :=GetHostByName(buffer);
    if phe = nil then Exit;
    pptr := PaPInAddr(Phe^.h_addr_list);
    I :=  0 ;
    while pptr^[I] <> nil do
    begin
      result:=StrPas(inet_ntoa(pptr^[I]^));
      Inc(I);
    end;
    WSACleanup;
end;