By default the Comparison
            tool will already exist in the Player (Display Tools) but will be
            muted.
         
         To enable the Comparison tool:
         
         
            - Do one of the following:
               
                  - Right-click in the Player and select
                     Comparison.
                  
- Press Shift
                        + C (or Shift + D for
                     the Display Modifier).
                  
- Select the Mute button in the tool options
                     of the Comparison Tool tab.
                  
 
To delete the Comparison tool from the
            Display Tools:
         
         
            - Select the Delete button in the tool
               options of the Comparison Tool tab. 
               This causes the Comparison
                  Pass Through tool to be used.