moved into a house with a jenn air refrigerator and there is no manual. so we don't know what the large clear plastic thing on the door is used for. It is about 20 inches long and 15 inches wide. it hangs on the door and takes up a lot of space that I am unable to use because I don't know what it is for. Please help me. I would be so appreciative. thankyou for any help you can give me.