Help attaching Babydan bed guard to bed!

[FrozenNorthPole]

I'm trying to attach the blue and white fabric/mesh fold down bed guard made by Babydan to a cot bed and cannot for the life of me understand how the strap works to attach it to the bed. Can anyone who's got one help?

Thanks Loopymumsy, that actually makes me feel better. I kept wondering if there was something really obvious that I was missing.

I managed to attach the strap in a way that steadied the guard against the mattress (DD1's little cotbed mattress was too light to keep it in place on its own, even pushed against the lip of the bed frame) but it involved fifteen minutes of swearing, two broken nails and a bigger number of half-hitches than has been seen since the girl guides scrapped their Knotting badge. God knows what we'll do if we ever have to remove the bloody thing again.