The fly is the hoverfly Episyrphus balteatus. It's very easy to identify this hoverfly due to the fact that the black lines on the abdomen are doubled. This is the only British species with this character. The orange colour is also a giveaway, and has led to it being called the Marmalade Hoverfly. I think your dragonfly is a common darter but I'm not an expert on these.
Thank you Clive, I was really struggling with the fly..... and have checked the dragonfly and from what I've found that is also correct... I needed to know them for a natural history photographic competition. Many thanks again, Helen