For our jammed sliding-side-windows, we tried Dan's suggestion, to spray silicon inside of each window track, especially the sticky UPPERS. Now the sliders open and shut smooth as....ever! Also, the best suggestion for reattaching the handle back on to the sliding-window was from the "Wanderer" with "Rear View Mirror Adhesives". Permanently attaching a handle back on to a slick glass surface is something else. The West Marine adhesive is the official Real Deal that Jeff was successful with. This whole window/handle OPERATION should work as long as both surfaces, the glass and the handle, are (nearly) STERILIZED first. BB+