Animate multiple objects with one Animation Group

Select Rendering-Animation Workspace to display animation tools.
Using Pick tool select all door objects.
Select Animation Group tool then click to define location of animation group axes and a red-green-blue axes appears.
Set Animation Time Line palette to Time = 0 sec.
Select Keyframe tool and click on the animation group axes only, (not the objects).
Set Animation Time Line palette to Time = 5 sec.
Use Rotate tool to rotate the animation group axes only and observe all the objects automatically follow the animation group axes.
Select Keyframe tool and click on the animation group axes.
Click Play button in Animation Time Line palette and observe the door moves from keyframe position 1 to keyframe position 2 in 0 to 5 sec’s.
Continue to Keyframe a new position for the animation group axes at different times to control the opening and closing of the door.