Thank you so much! That all makes sense, and I'll have a look,.

P.S. All sorted - thanks again!

I'm probably being dumb - if so, apologies.... I have a fairly simple PHP-generated page of photogaphs. When I select a photograph, the slide show controls are displayed, but in duplicate. Any idea of what I have done wrong? https://braemoor.co.uk/hebden/oldimages.php My HS parameters are: hs.graphi...