function recognize(filename: string; apikey: string; is_phrase: boolean; is_regsense: boolean; is_numeric: boolean; min_len: integer; max_len: integer): string;
var
	ftype,tmpstr,captcha_id: String;
	i: integer;
	http: TIdHTTP;
	multi: Tidmultipartformdatastream;
begin
	if FileExists(filename)=false then begin result:='ERROR: file not found'; exit; end;

	ftype:='image/pjpeg';
	if strpos(Pchar(filename),'jpg')<>nil then ftype:='image/pjpeg';
	if strpos(Pchar(filename),'gif')<>nil then ftype:='image/gif';
	if strpos(Pchar(filename),'png')<>nil then ftype:='image/png';

	multi:=Tidmultipartformdatastream.Create;
	multi.AddFormField('method','post');
	multi.AddFormField('key',apikey);
	multi.AddFile('file',filename,ftype);
	
	if is_phrase=true then multi.AddFormField('phrase','1');
	if is_regsense=true then multi.AddFormField('regsense','1');
	if is_numeric=true then multi.AddFormField('numeric','1');
	if min_len>0 then multi.AddFormField('min_len',inttostr(min_len));
	if max_len>0 then multi.AddFormField('max_len',inttostr(max_len));

	http:=TIdHTTP.Create(nil);
	tmpstr:=http.Post('http://ac-service.info/in.php',multi);
	http.Free;
	captcha_id:='';
	if strpos(Pchar(tmpstr),'ERROR_')<>nil then begin result:=tmpstr; exit; end;
	if strpos(Pchar(tmpstr),'OK|')<>nil then begin captcha_id:=AnsiReplaceStr(tmpstr,'OK|','');   end;
	if captcha_id='' then  begin result:='ERROR: bad captcha id'; end;
	for i:=0 to 20 do 
	begin
		Application.ProcessMessages;
		sleep(5000);
		http:=TIdHttp.Create(nil);
		tmpstr:=http.Get('http://ac-service.info/res.php?key='+apikey+'&action=get&id='+captcha_id);
		http.Free;
		if strpos(Pchar(tmpstr),'ERROR_')<>nil then begin result:=tmpstr; exit; end;
		if strpos(Pchar(tmpstr),'OK|')<>nil then
		begin
			result:=AnsiReplaceStr(tmpstr,'OK|','');
			exit;
		end;
		Application.ProcessMessages;
	end;
	result:='ERROR_TIMEOUT';
end;