Mass-Update
Setting this property to "1" inhibits isCOBOL framework to repaint the List-Box control every time the program modifies it. This practice is recommended to increase performance when a large number of changes are applied to the List-Box control. At the end of the process it is necessary to reset the property to its default value of "0" to see the changes.
 
Example - Add three items in mass update mode
procedure division.
...
  modify screen-1-lb-1 mass-update 1
  modify screen-1-lb-1 item-to-add "item 1"
  modify screen-1-lb-1 item-to-add "item 2"
  modify screen-1-lb-1 item-to-add "item 3"
  modify screen-1-lb-1 mass-update 0
...