How do you climb a ladder

Im having trouble getting the first person controller from the package to be able to climb a ladder. Im new to coding but can someone help me out? I made the ladder on blender. here is a picture

http://forum.unity3d.com/threads/13193-ladder-example

http://answers.unity3d.com/questions/35353/how-to-climb-up-a-ladder

Since it is first person, you shouldn’t have to worry about animations

The first link shows you the best way to do it.

http://☂.net/umbrella/2010/11/unity3d-ladders/