isCOBOL Evolve : User Interface : Controls Reference : LIST-BOX : Styles : { Permanent | Temporary }
{ Permanent | Temporary }
Permanent
A control with this style applied can be destroyed only by using the DESTROY statement or when the parent window is destroyed. A permanent control is more efficient than a "temporary" one since it is not created each time a DISPLAY statement is executed. This style is set by default.
Temporary
Temporary controls are destroyed when a DESTROY statement is executed, when the parent window is destroyed, when another control is created in its same position, or when a Screen Section containing a BLANK SCREEN keyword is displayed. Temporary controls are less efficient than "permanent" ones since they are created each time a DISPLAY statement is executed.
 
Example - Define a temporary list-box
screen section.
...
  03 screen-1-lb-1 List-Box
     temporary
     line 5.7
     column 3.1
     size 34.6 cells 
     lines 15.5 cells 
     id 1.