thanks again dirgas for quick reply and i check my setting its default, public. when i use opera browser on my computer i can comments or reply to anyone but when i use opera mini on my blackberry then i can't because there is not option.

hi dirgas, thanks for reply
when i click this link it gives me the comment bar of "Hungary near future" video. it means i can comment on this video. but still i can't comment on other videos. if there will be comment section that i can click it and then write a comment, that would be much better.

i am using opera mini on my blackberry and i can watch videos and i can like/dislike videos but there isn't any comment option or reply option if someone comment on my video. i am using latest version of opera mini.