SCRIPTING TROUBLE PLEASE HELP!!!!

ok so i am super new to unity and i need help. i had trouble useing the machine gun script so i got a new script from some1. now i fixed the problem but how do i get the old script back, the defualt 1? PLEASE HELP!!!

just download the FPS tut again

next time don“t replace scripts, instead rename them to a similar name, so you have a backup.