Private Sub Command0_Click()
Dim db As DAO.Database
Dim cnt As DAO.Container
Dim doc As DAO.Document
Dim prt As DAO.Property
Set db = CurrentDb
Set cnt = db.Containers!Databases
Set doc = cnt.Documents!summaryinfo
On Error Resume Next
doc.Properties("Author") = "John Doe"
' if property not found, create it.
If Err = 3270 Then
Set prt = db.CreateProperty("Author", dbText, "John Doe")
doc.Properties.Append prt
End If
End Sub