Is it Erwin or Ervin?

The following pictures were taken on two separate occasions. Every time there is a celebration at Erwin's place, I am always invited to attend. The first two pictures below were taken on August 31, 2008 during Miko's birthday. Miko is the "apo" of Erwin. The other two were taken a few months earlier (maybe May 2008).

Erwin and Ervin (or is it Ervin and Erwin?)

Miko, the celebrant, Erwin's apo

Anne (Erwin's daughter), her hubby Mark, Miko and Ervin