If you dont have a warrenty to worry about just pop off the cover.
Most players will have two screws holding down a plate right across the dvd. You can just take them out and lift out the dvd. Yhen put it back together. Some Like mine for some idiotic reason are one solid piece inside in that case carfully push down on the dvd to nock it off the top then eject it.
PS the player can be on when you do this but have the dvd be STOP'd so the player isn't trying to read it.
cas, July 2004
my last reply had some spellcheck issues. the dvd was from the library and I tapped it on top.
sorry about the errors
dman, June 2004
I had this happen to me with a dvd from the librar because they put sticky tape on the top and it stuck in my player but I could still open my machine tray. Anyway with the tray closed the dvd is probably stuck in the same way. I gave it a forceful but gentle tap on to with my hand and i heard the dvd fall back in the tray. I know it sounds stupid but it worked. Hope this helps
dman, June 2004
edit
I can answer this question...
How do I get a DVD that is stuck in my player out?