Performance problems can be caused by many things and we don't have enough information. Please read the following article to be able to post what we need to help you.
http://www.sqlservercentral.com/articles/SQLServerCentral/66909/
Luis C.
General Disclaimer:
Are you seriously taking the advice and code from someone from the internet without testing it? Do you at least understand it? Or can it easily kill your server?
How to post data/code on a forum to get the best help: Option 1 / Option 2