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function exists_url(URL: String): Boolean;
var
  Session, thefile: hInternet;
  index,CodeLength: cardinal;
  Code: array[1..20] of Char;
  res: PChar;
begin
  Result := False;
  Session := InternetOpen('InetURL:/1.0',INTERNET_OPEN_TYPE_PRECONFIG,nil,nil,0);
  if Assigned(session) then
  begin
    thefile := InternetOpenUrl(session, pchar(URL), nil, 0, INTERNET_FLAG_RELOAD,0);
    Index := 0;
    CodeLength := 10;
    HttpQueryInfo(thefile, HTTP_QUERY_STATUS_CODE, @Code, CodeLength, Index);
    res:= pchar(@Code);
    if res = '200' then
      Result := True;

    if Assigned(thefile) then
      InternetCloseHandle(thefile);
  end;
  InternetCloseHandle(session);
end;