{:Converts Ansi string to Unicode string using specified code page.
 @param s Ansi string.
 @param codePage Code page to be used in conversion.
 @returns Converted wide string.
}
function StringToWideString(const s: AnsiString; codePage: Word): WideString;
var
 l: integer;
begin
 if s = '' then
  Result := ''
 else
 begin
  l := MultiByteToWideChar(codePage, MB_PRECOMPOSED, PChar(@s[1]), - 1, nil, 0);
  SetLength(Result, l - 1);
  if l > 1 then
  MultiByteToWideChar(CodePage, MB_PRECOMPOSED, PChar(@s[1]),
  - 1, PWideChar(@Result[1]), l - 1);
 end;
end; { StringToWideString }