thans all of your reply and appreciation of this performance.
the accompaniment MIDI file is downloaded from internet site(taiwan),it's name is "Christmas wish". i do not know who is it's author. I extract the piano track and translate it into music score,my son played the piano part along the modified MIDI file being palyed on the PSR2000.

having your encouragement,he will make more efforts on studing keyboard playing skill.

to Scottyee:Christmas is know very well in china,especially among young people,but it is not officially celebrated in China now.i hope some day you can visit your ancestral place - china.