var haystack : array of String = ["Zig","Zag","Wally","Ronald","Bush","Krusty","Charlie","Bush","Bozo"];

function Find(what : String) : Integer;
begin
   Result := haystack.IndexOf(what);
   if Result < 0 then
      raise Exception.Create('not found');
end;

PrintLn(Find("Ronald")); // 3
PrintLn(Find('McDonald')); // exception