selectlanguage starts not automatically

[Jens-Olaf Lindermann]

Hi ng!

I have a little problem with emacs and auctex. In my file 

\documentclass[12pt]{article}
\usepackage[german,polutonikogreek]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{soul}


\begin{document}\selectlanguage{german}
some stuff in german \selectlanguage{polutonikogreek} some stuff in old
Greek
\end{document}

I have to reload the babel-package with the language-option every time, when
I re-open the file, because auctex seems not to no the package with C-c RET
and sel- autocompletion. What can I do to load this package every time
automatically?

Jens

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