First time using a curtain side tomorrow - advice

Just spent my first windy day with a curtain sided 7.5 tonner, had 10 minutes wrestling with it, I opened one side for unloading then realised I couldn’t undo the straps so had to open the other side, big mistake thought I was going to lose the curtain. Mental note made for future, if needed turn wagon around, don’t open both sides at once in the wind.

Gav