gettext .po msgid_plural failed

Hi All,

I am using gettext and .po files for my translation, however, I found it very difficult to apply plural form translation, is there anything goes wrong?

in controller:

<%=h _("You received %{no_friend} friend invitation") %{:no_friend => pending_friends_for_user.length } %><br/>

in en/myapp.po

msgid "" msgstr "" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=utf-8\n" "Content-Transfer-Encoding: 8bit\n" "Plural-Forms: nplurals=2; plural=n == 1 ? 0 : 1;\n" "X-Poedit-Country: UNITED STATES\n"

#: app/views/friends/_pending_friends_for_user.rhtml:- msgid "You received %{no_friend} friend invitation" msgid_plural "You received %{no_friend} friend invitations" msgstr[0] "You received %{no_friend} friend invitation" msgstr[1] "You received %{no_friend} friend invitations"

Is there anything goes wrong?

Any help is appreicated, I hope not making obvious mistake here.

Thanks again! Arthur