It's probably dead or dying. Most have a pinhole under the tray, where you can manually eject it with a paperclip. You can try to manually eject and close the tray.
+1. The drive belt on the tray mechanism can go bad pretty easily on the tray. That's why you should use the open/close button instead of 'forcing' the tray closed. The cost of a new drive is probably less than having the drive belt replaced.