How can I fix wiper problem on my 2002 seat Alhambra?

Hi can anyone help, I have a 2002 Seat Alhambra and all of a sudden my front washers wont work and the wipers will only work on an odd occasion if i fiddle with the stalk,I have tried two second hand stalks and still have the same problem.
the rear wipers work but no wash can anyone help please

Alan
December 2010