http://w3n-a.blogspot.com/2008/11/pitch-and-power.html

No discussion of climbs and descents would be complete without
touching on the question of what controls altitude and what controls
airspeed. The pilot must understand the effects of both power and
elevator control, working together, during different conditions of
flight. The closest one can come to a formula for determining airspeed/
altitude control that is valid under all circumstances is a basic
principle of attitude flying which states:

"At any pitch attitude, the amount of power used will determine
whether the airplane will climb, descend, or remain level at that
attitude."

http://w3n-a.blogspot.com/2008/11/pitch-and-power.html