Inserting a zipper in a bag - specific question

I am making a small zippered bag from a piece of a blue jean leg.  Because of the way I made it from the jeans, I currently have what looks kind of like a flapless envelope - it's sewn on three sides, and it's flat.  I want to use the zipper as the top side.  I was thinking I remembered there being a way to sew the zipper into this, such that I can use the opening of the zipper itself to turn it right-side-out, but the details escape me.  Can anyone remind me, or am I just imagining such a possibility.

Hi.....I've added zippers to bags of this style but I sew the zipper to each edge of the opening before sewing the other 3 sides.  Remember to unzip the zipper before sewing the other 3 sides then you can turn the bag right side out through the zipper opening.
Hope this helps!

Hi,
   the following link is to a zippered pouch tutorial on Lisa's Uhandblog. Her little pouch is lined but just omit that if you are not lining yours, the principal is the same anyway.

Hope this helps.   http://u-handbag.typepad.com/uhandblog/2007/02/had_a_quiet_wee.html

Helen O'B.