R help - May 2006 - Thanks for help

Hello David and Spencer,

thank you for your replies!
The systemfit-package was exactly what I was looking for.
The only little drawback is, that the nonlinear systemfit does not 
support predifined weights yet (in oder to ensure homegenity of 
variances when predictios are hetescedastic)

Thanks also to Katharina, who mailed me offline and drew my attention to 
the nls and the nlm function. This answerd my second question.

Thomas