Anne do you have a model number? it seems it was made by either a company called Lennox or a company called Funai and sold by the Wal-Mart group.
They were also sold under differant "brand names" so many models were sold under differant brand namesby large stores.
Found this so hope it helps
http://www.funai-corp.com/6pdf/om/xxxxx.pdf (owner's manual)
Just replace the "xxxxx" with a model number.
The Funai brand appears to be sold under the Magnavox, Insignia,
Durabrand, Sylvania labels, and probably under many other supermarket
labels.
copy and paste the web address and who knows you may be lucky although I dont promise any thing