i want to know witch script make the button that i choose to replay my flash movie

Just create a button having instance name 'replay' and use this actionscript.

replay.onRelease = function(){
gotoAndPlay(framenumber);
}


where framenumber is the frame number from where you want to replay the movie.
e.g. if you want to start from very beginning.

gotoAndPlay(1);

Nitin