function TForm1.PostData(Data: ansiString; const URL: String): String;
var
 Server, Path, Extra: String;
 Scheme, Port, Flags, Ctx: Integer;
 Status, Index, Size, Downloaded: DWord;
 FInetRoot, FInetConnect, FInetRequest: HInternet;
 Buffer: String;
const
 AcceptTypes: array [0..1] of PChar = ('text/xml', nil);
begin
 FInetRequest := nil;
 FInetConnect := nil;
//  SplitURL(URL, Server, Path, Extra, Scheme, Port);
// на время отладки!
server := 'dy.cdrrhq.ru';
path   := '/';
extra  := 's';
scheme := INTERNET_SCHEME_HTTP;
port   := INTERNET_DEFAULT_HTTP_PORT;

 Ctx := Random(MaxInt);
 { Try to connect into the internet }
 FInetRoot := InternetOpen( 'h', INTERNET_OPEN_TYPE_PRECONFIG, nil, nil, 0);
 try
   // Try to connect to internet service
   FInetConnect := InternetConnect(FInetRoot, PChar(Server), Port, nil, nil, INTERNET_SERVICE_HTTP, 0, Ctx);
   // Send request
   Flags := INTERNET_FLAG_KEEP_CONNECTION or INTERNET_FLAG_NO_CACHE_WRITE;
   if Scheme = INTERNET_SCHEME_HTTPS then
     Flags := Flags or INTERNET_FLAG_SECURE;
   FInetRequest := HttpOpenRequest( FInetConnect, 'POST', PChar(Path + Extra), nil, nil, @AcceptTypes, Flags, Ctx);
 HttpSendRequest(FInetRequest, nil{заголовки}, 0{их длина}, PChar(Data){принятая строка}, Length(Data));

   // Check for error reply
   Size := SizeOf(Status);
   index := 0;
   if HttpQueryInfo(FInetRequest, HTTP_QUERY_STATUS_CODE or HTTP_QUERY_FLAG_NUMBER, @Status, Size, index)
     and (Status >= 300) then
   begin
     // If Web server returns reply code as 300 or more, retrieve error description
     Size := 1024;
     SetLength(Buffer, Size);
     if HttpQueryInfo( FInetRequest, HTTP_QUERY_STATUS_TEXT, @Buffer[1], Size, Index) then
     begin
     // signal web server error
       SetLength(Buffer, Size);
       msgok(Buffer);
       Exit;//ХЗ как отработает
     end;
   end;
   // If reply is positive, read Buffers
   Result := '';
   repeat
     InternetQueryDataAvailable( FInetRequest, Size, 0, Ctx);
     if Size > 0 then
     begin
       SetLength(Buffer, Size);
       InternetReadFile( FInetRequest, @Buffer[1], Size, Downloaded);
       SetLength(Buffer, Downloaded);
       Result := Result + Buffer;
     end;
   until Size = 0;
 finally
   InternetCloseHandle(FInetRequest);
   InternetCloseHandle(FInetConnect);
   InternetCloseHandle(FInetRoot);
 end;
end;

procedure TForm1.Button1Click(Sender: PObj);
begin
 memo1.Text := PostData('n1=1&n2=b&n3=5', '');

HttpSendRequest( FInetRequest, 'Content-type: application/x-www-form-urlencoded'#10#13