You know the double pane windows in houses. 20 yeaRS AGO IF YOU HAD A BAD/ FOGGED UP WINDOW YOU COULD TAKE THE SASH OUT AND TAKE IT TO W, Bird COMPANY ON EAST BAY STREET AND THEY WOU;D REPlACE THE FOGGED UP PART BY PUTTING NEW DOUBLE PANE GLASS I NTO YOUR WOOD FRAME . Took maybe 3 days. They are not there anymore. Someone must do it rather than replacing the entire window?