Sorry for the german text, it was my mistake! The answer is for Frank only! -- Andreas Schmidt, IPF-Universitaet Karlsruhe, Englerstr. 7, D-7500 Karlsruhe Telefon: +49 721 608 3676 Fax: +49 721 694568 Internet: schmidt at ipf.bau-verm.uni-karlsruhe.de