Many thanks for the replies, What I did was just put up a post saying Firefox was required. There was half dozen responses saying no problems, no one replied it was not acceptable. The slide show now has been up now for around 8 hours there have been more than 30 downloads and no one has said anything, so it must be OK. My experience on such things is that people will complain if theres a problem but most will say nothing if its OK, ie one needs to consider it a broadcast situation. If feedback is required the audience will have to be pressed in some way. A classic method widely used particularly in broadcast radio is to broadcast a delibrate mistake. I have used this in the past under similiar situations, works perfectly. Lindsay