In the .Click() I create a messagebox with the question if the user wants to process the selected items. The messagebox takes the focus from the listbox. The specific .click() code I use is the following. I changed the "real" data handling with a messagebox for testing purposes.

FOR lnCount = 1 TO .ListBox.ListCount
IF .ListBox.Selected(lnCount)
MESSAGEBOX(TRANSFORM(.ListBox.List(lnCount,1)))
ENDIF
ENDFOR