problem with mplayer

currently i have mandrake 9.0 installed i watch dvds with mplayer by running the command "mplayer -dvd 1" but i irealize for some dvds this does not work and even changing 1 to 2 or even 3 does not solve the problem either what happens is that i only get to watch a chapter a time and not the whole movie. I have an idea that the command is suppose to be "mplayer -dvd title" but how do i get the title of the dvd that is my problem. is there a command that is universal for all dvds instead of "mplayer -dvd 1" i am not really a fan of xine it crashes too easily and it can't play some media files i have like .DAT for example. HELP PLEASE!!!!!