Sleeping Bag with broken zip

I have a JRC 5 Season Storm sleeping bag which I have been happy with. I bought it in summer 2004. The zip is broken, though: it has come off the bottom of one side(if you know what I mean).
Does anyone know if I can fix it or where I can get it fixed?

-------------E
------------/-E
Make a snip (/) through the teeth in the zip as close to the end (E) of the side the zipper has detached from, then slip the zipper back up, sew half a dozen stitches(just above the snip, to the other side to bring both sides back together)and the zip will function normally and will close down to the spot where the stitches are across.
4lb mono makes a strong thread.

Thanks Terry - will try that.

or call it a throw over !