Reattaching the cord to velux blackout blind?

So the cord on my velux blind seems to have come unattached on the right side.

The blind itself still goes up and down easily, except the right side of the blind is slightly above the left.

There is a cord that goes from the top left corner of the fitting to the bottom right corner when the blind is fully retracted. My guess is that it's come off the blind but I have no idea how to reattach it.

I've taken a photo of the blind when fully retracted, in case that helps (although it's a bit faint!)

http://i.imgur.com/CU3vvzf.jpg

Hannah J
June 2015