How to fit an linear model withou intercept

Please could anyone help me?
How can I fit a linear model where an intercept has no sense?

Well the line has to have an intercept somewhere I suppose.
If you use the site search facility and look for "known intercept" 
you will get some clues.

Thanks in advance..

Michael

Michael Dewey
http://www.aghmed.fsnet.co.uk