I've developed some code that will alter the subject line of an email
message selected in Outlook Explorer view based on a button clicked on
a custom toolbar.

I've succesfully delivered the code to 3 out of 5 user machines that
need the functionality - two machines that I'm having a problem with
are generating a Runtime Error 13 at the line in the {} brackets below
- ANY help would be greatly appreciated!

Public Sub ChangeSubjectLine()

Dim objApp As Outlook.Application
Dim GetCurrentItem As Outlook.MailItem
Dim ReplyCurrentItem As Outlook.MailItem
Dim CurrentSubject As String
Dim myNameSpace As Outlook.NameSpace
Dim myInbox As Outlook.MAPIFolder
Dim myDestFolder As Outlook.MAPIFolder
Dim myItems As Outlook.Items
Dim myItem As Object
Dim WorkType As String
Dim ReplyBody As String
Dim AssigneeName As String
Dim AssigneeNum As String
Dim IncludeFolder As Boolean

Set objApp = CreateObject("Outlook.Application")
On Error Resume Next
Select Case TypeName(objApp.ActiveWindow)
   Case "Explorer"
       {Set GetCurrentItem = objApp.ActiveExplorer.Selection.Item(1)}
   Case "Inspector"
       Set GetCurrentItem = objApp.ActiveInspector.CurrentItem
   Case Else
       ' anything else will result in an error, which is
       ' why we have the error handler above
End Select

Code continues...

Thanks!
Jeff