Test for no listbox selection

[John]

I have a userform w/ a listbox that has a few items. How do I test to be
sure at least one item is selected when OK is clicked. None of the following
will display the MsgBox to find the omision of listbox selection:
If Len(Listbox1) = 0 Then MsgBox "..."
If IsEmpty(Listbox1) Then MsgBox "..."
If Listbox1 = "" Then MsgBox "..."
How do I tell if no selection has been made?

I appreciate your help, -John

 

[Rick Rothstein]

The ListIndex property of the ListBox will be -1 (minus one).