Some of our windows open by sliding up and down. At the top of the sliding window are 2 levers that are moved at the same time to release the pegs and allow the window to move. Tonight 9ne of the levers has jammed and we cannot either raise of lower the window. It is stuck open with 6 inches to go. Has anyone run across this before? And are there any suggestions on what to do? Going to be a chilly evening