Modules & VBA :: Enable Command Button When Item Selected From List Box

I have a simple listbox (single column, no multi-selection).I want to enable a command button when the user selects an item in the listbox / disable it if no items are selected.I'm using the AfterUpdate event of the listbox, as follows :

Code:

Private Sub lstOptions_AfterUpdate()
Select Case Me.lstOptions.ItemsSelected.Count
Case 0
Me.comConfirm.Enabled = False
Case Else
Me.comConfirm.Enabled = True
End Select
End Sub

But when I select an item from the listbox, and debug the code, the Count is always zero? Even though I can see the item selected??