Thanks to all who replied with advise. The leak was eventually found and it was the head gasket drivers side front. I tried a can of "not so cheap" Rislone and hey presto no more leak. The level in the reserve bottle has not moved so mybe I was lucky as $70 was worth a try before shelling out big bucks for a major repair. One again thanks.

Three weeks and the res bottle has not moved! Best $70 bucks i've spent in a while....