How do I make slideshows always start on first slide?

I’ve put several slideshows into a website. They run OK but at the end of the slides, they start running backwards through the slides. I don’t really care about going backwards but I’d like each new viewer to view the slides from the first slide rather than somewhere in the middle of the slides. How do I make the slide show start at the first slide for each new viewer? Thanks for any help. James