Thanks, Bastien. It's the default value - I've not changed it:

org-file-apps is a variable defined in `org.el'.

Its value is ((auto-mode . emacs)

("\\.mm\\'" . default)

("\\.x?html?\\'" . default)

("\\.pdf\\'" . default))

On Mon, Feb 4, 2013 at 4:20 PM, Bastien <bzg@altern.org> wrote:

Hi Zhenjiang,

zhenjiang xu <zhenjiang.xu@gmail.com> writes:

> when I type the keys `C-c C-e b', the html is generated but it is
> opened in emacs instead of an internet browser. Does anyone know
> why?

Check the value of `org-file-apps'.

C-h v org-file-apps RET

Hope this helps,

--
Bastien