Mx-5 saggy roof

[deevlash]

My mums got an MX-5 and when she puts the roof up its a bit saggy at the back. Theres a support which comes from the main rear roof support that, when pushed back makes the cloth roof taught but after about 5 minutes it slips back and the rear goes saggy again and my mum doesnt have the strength to push it back properly anyway. The bar has 2 cords attached to it, one on either side and the ends of these have 2 holes in it which must have had bolts through them at some point but dont now. Anyone know how these attached and if they can help the taughtening beam stay in place? thanks in advance

[Munter]

I cant help you except to say i'm sure someone on www.mx5ocforum.co.uk has had this or knows how to fix it.