How to make fix size window or screen>

[prince_of_persia]

Hello
I`ve been using VLC media player for a long time. The problem is, when I open a movie, screen size (not in maximize) its half of my screen. But when I close VLC and open a different movie the screen size is is different than before. Actually, I know that its depend on the quality of video but its annoying for me as I have to resize it every time I open it. So Please tell me how to make its size fix, like other player ie. KM player and Splash player.
I specially created this account for this question and I would really appreciate it if you can help me.
Regards

[VLC_help]

Tools -> Preferences (show settings: All) Video (save and restart VLC after changes)