Character Move Forward after Camera Perspective

When I hold the forward key down my game character does not move directly forward it moves diagonally.

This Is happening because I say the forward direction is the +ve Z axis but when the camera perspective is applied to my scene the perspective makes my character look like it is moving diagonal.

How do I make my character move straight when camera persective is applied?

similar topic:link text

I would suggest trying to find the forward direction of the camera and just apply that as the direction in which you want your character to move while holding the forward key.