can anny one help me please if i put a mp4 on my memory stick (the one that goos in my phone) i cant play it but if i put in the phone and not on the card i can play it is there some thing i do wrong

perhaps telling us which phone model?

k750i

do you attempt to play it when it is connected with the cable? if so, your duo card will not be available via the phone menu.
disconnect and attempt to play it.