I want a simple message box that displays whenever I create a new selection
in a worksheet. The message box needs to display both the address of the
last selection and the address of the new selection. I have the following
solution:

Dim LastSelected As String
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
MsgBox LastSelected & Target.Address
LastSelected = Target.Address
End Sub

This works fine except for the first time through, when LastSelected is
empty. How can I get the initial selection to display in the message box?

Many thanks.