Thank you so much, but would you believe I made the same thing yesterday. All I did was cut my fabric 14" x 37" and the straps were 4 inches wide and as long as I wanted them. I also had to make a facing to sew the straps onto the bag, can just attach to the bag on the outside if you want and sew them good so they don't pull off, then I sewed up the sides and put a pocket between the straps to fold the bag into and there I had it. In other words make a bag and just add a pocket yo the outside.
Try this before you buy the pattern.
Thank you again for your information.
Patty