Thanks for your replies
Your answers were as I feared (and half-expected!) and so I've started from scratch. I've been taking her outside every hour for the last couple of days and I'm praising like nuts and giving treats when she goes! So far we've had one accident inside which was my fault for not paying 100% attention
saying 'NO' and taking her outside was pointless because I didnt catch her in the act. I'm hopeful she'll get the hang of it again quickly! xxx xxx