GE 1.5 Beta Rotation?

I'm designing a space-shooter, and I was wondering how I can set rotation? Like, when you press down, I want the ship to turn down-ward at an angle, same with up. How can I set the rotation based on an angle? Example:
- Code: Select all
if(angle<45)
{
angle+=(45/10); //10 frames to complete angle change
Rotate?
}