I you have a listbox with some rows, users may click on a row; and the row is selected. If users click on the white space below the rows, nothing is selected. One can detect this and do whatever is necessary.
The problem in Windows is that the previously selected row retains a gray outline. My tester felt this would be confusing.
Searching the Forum I found a suggestion to simply reload the listbox. This seemed a bit like overkill.
Here's something I tried that appears to work: i appended a blank row, selected it, and then removed it. This is in the Change event if me.listindex = -1
row = me.lastindex
me.selected(row) = true
Hope this helps.