Play Fly-Through
Click 3D View | Fly-Through | Play or the 
button to play the current fly-through. A fly-through must be created by clicking the 3D View | Fly-Through | Create/Edit command before the Play command is available.
Once a fly-through has been created, click 3D View | Fly-Through | Play to view the fly-through, click 3D View | Fly-Through | Record to record the fly-through, or click 3D View | Fly-Through | Create/Edit to modify the fly-through.