[XeTeX] Problem with Mapping=tex-text

[Chaiwat Jidogang]

Hi,

I think I have some problem with text mapping.
I want to use the default Computer Modern fonts and I want the usual
TeX code produce `single-quote', ``double-quote'', en-dash (--), and
em-dash (---),
so I put \defaultfontfeatures{Mapping=tex-text} in, as shown below.
However, xelatex the following code didn't produce the quotes and
dashes as I want.

Could anyone tell me what I'm missing. The following are my code.

%----------------------------------------------------
\documentclass[11pt,a4paper,twoside,openright]{report}
\usepackage{fontspec}
\defaultfontfeatures{Mapping=tex-text}

\begin{document}
``quote''

en-dash (--)

em-dash (---)
\end{document}
%----------------------------------------------------


Thank you,
--
Chaiwat