isCOBOL Evolve : User Interface : Controls Reference : SCROLL-BAR : Styles : Track-Thumb
Track-Thumb
The keyword Track-Thumb is supported for compatibility but is treated as commentary. This style has no effect.
 
Example - Define a scroll-bar with track thumb
screen section.
...
  03 screen-1-sb-2 Scroll-Bar
     line 39.1
     column 12.8
     size 2.4 
     lines 30.8
     id 10
     track-thumb
     .