Thumb-Position
This property allows you to set or retrieve the first visible item in a list-box. Its value is the index of the item, not the text.
Use this property only when the 
Paged style is not set.
 
Example - retrieve the text of the first visible item in the list
procedure division. ...    inquire screen-1-lb-1 thumb-position w-index    modify screen-1-lb-1 query-index w-index    inquire screen-1-lb-1 item-value w-text ...  |