transfer anonymous profile to authenticated user

 Hello, I have a profile as shown below where the user can add items to a shopping cart. Once the user logs in I want to transfer the the cart items to the authenticated user. I have read that this is done in the global.asax page. I have added that page and added a Profile_MigrateAnonymous sub. My question is how and where do you call this sub in the global.asax page?
 
Here is the Profile_migrateAnonymous sub:
Private Sub Profile_MigrateAnonymous(ByVal sender As Object, ByVal e As ProfileMigrateEventArgs)
        Dim anonProfile As ProfileCommon = Profile.GetProfile(e.AnonymousID)
        Profile.ShoppingCart = anonProfile.ShoppingCart
        AnonymousIdentificationModule.ClearAnonymousIdentifier()
    End Sub
 Here is my profi ...