Ebay offers 10x10 Enclosure Zipper Side Walls Kit Panels For EZ Pop Up Canopy Gazebo Tent for $69.99 free shipping.

Product Description:

4 Zipper End Sidewalls (3 Solid walls + 1 Entry Door Wall), canopy top not included. 3 Solid walls + 1 Zip Door Wall with roll up door and screen window.
Full Horizontal Velcro on sidewalls, attach with the canopy top cover by velcro easily. Strengthen strape on bottom edge, Make the wall strong and durable.
Fit for most 10x10, 10x15,10x20 Feet Straight Leg pop up commercial canopy, portable tent, Beach Canopy, Shade Canopy.