Unable to Play MP4 in W660i

Hi Friends,
I have Sony Ericsson W660i model. I copy some MP4 format videos in my mobile. But mobile doest not play the video, audio only enable, video is not displayed.
Pls helpme , hoe to ply MP4 format video. or any other players is needed.

Awaiting for your favorable reply

convert the video in this resolution 240x320 or 176x220

You can play:

176 x 144
320 x 240
352 x 288

But 640 x 480 or more - cann't. Use Format Factory and choose Sony Ericsson phone for convert.