"............Automatic vents are a mustmustmust ......."

YES ........ but don't get them yet, wait for the Argos Spring/Summer
catalogue, they do a very good automatic vent for around £15.00.,
I have had one working for the last 8 years,

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk
***2004 catalogue now available***