mplayer resolution problem

i was facing this problem when installed MPlayer-1.0rc1 on ubuntu 7.10, the problem was that the video would come up only in the center of the screen even in the full screen mode ,i had installed the player from source . Now there are two solutions for this, the first one works perfectly , but the second one is a little problematic .They are :
1. Create an alias to the mplayer command and place it in the bash configuration file, so the line to be placed in the file is:
alias mplayer='mplayer -zoom 200'
and place this in the file ~/.bashrc . This works fine if u are running mplayer from the command line , i will post the next method a little later .....