I am writing a VBA app for Outlook and I have declared a global variable at the top of the ThisOutlooksession object code as follows:

Public WithEvents oMailItem As Outlook.MailItem

when I try to access oMailItem in a form which is part of the project I get an error 'Object undefined'. What am I doing wrong?
shouldnt the variable be available if it is declared as global??
I would appreciate any help with this.