How do I use my Baby Nelf script online?

So I just found a script I been looking for for a year now ( the script: http://pastebin.com/raw/KSYta6ys ) and when I did a local script it worked soooooo good in studios. But when I went to the online game nothing happened! Anyone know why this is happening? I tried that "WaitForChild" thingy but I was too confused!