Any advice on how to get a burned DVD-R to play on my Sony DVD player? It works fine on my computer.?

It is a Sony DVD-R 4.7 GB disk, a burned movie. It just says no disc when inserted into the DVD player. It is DVP NS400D model number. any advice or things I should try? Would using DVD+R help?Any advice on how to get a burned DVD-R to play on my Sony DVD player? It works fine on my computer.?
Sorry, that model does not play DVD-ROMs.





Here's the manual:





http://www.docs.sony.com/release/DVPNS40鈥?/a>