[Rotation:X Axis Specify] command updates CPlane by the steps:
While
Specify the origin of CPlane
prompt is displayed, specify a new origin of CPlane.
While
Specify X Axis
prompt is displayed, specify a new X-axis direction of CPlane. The straight
line from the origin specified in Step 1 to the point in this
procedure is X-axis of the updated CPlane.
In the screen preview, updated X and Y-axis are dynamically displayed accorging to the mouse cursor movement.