http://en.wikipedia.org/wiki/Glenn_Howerton

Glenn Franklin Howerton III (born April 13, 1976) is an American actor of television and film. He is best known for his role as Dennis Reynolds on FX's It's Always Sunny in Philadelphia (on which he is also a writer and executive producer). He also played Corey Howard on the short-lived 2002 sitcom That '80s Show and appeared in the 2008 horror film The Strangers.

Sources

1. U.S. Public Records Index, Volume 2; Name: Glenn F Howerton; Birth Date: 13 Apr 1976; Address: 333 Washington Blvd Ste 33, Marina Del Rey, CA, 90292-5136. 1233 N Crescent Heights Blvd # A, West Hollywood, CA, 90046-5029. 8205 Santa Monica Blvd Ste 12, West Hollywood, CA, 90046-5963. 438 S Venice Blvd Apt 5, Venice, CA, 90291-4695.