I am using the following code to update records in an Access 97 Database:

Dim oWs As Workspace
Dim oDb As Database
Dim strSQL as string

UserID = List1.Text

Set oWs = Workspaces(0)
Set oDb = OpenDatabase("c:\temp\DB1.mdb")

strSQL = " INSERT INTO Table1 " _
& "(Field1) VALUES " _
& "('" & UserID & "');"

List2.AddItem List1.Text

oDb.Execute strSQL
oDb.Close

This works fine BUT, how can I do a check on Field1 in Table1 to make sure that a duplicate entry is not made ???