missing unknown hardware

I have rented a house with windows that slide up and down. I'm not sure if that is what is called double-hung style. The label on the latch hardware on top is "certainteed". One window which is 14" high (outer dim. of height) is missing ALL hardware that keeps in place. The design is such that the frame is just barely the same or larger than the width of the moving part. So that darn thing simply falls out with any disturbance and it certainly will not stay up. I have added three pictures of the dysfunctional unit and two pictures of the bottom and top of another one which is working OK. Please see if you can help identify what hardware to insert to stabilize this. I can get more pictures if needed. Your help is much appreciated.