NotInList event adds records twice

[Anita Mossey]

I have a table named tblSkills consisting of two fields named
ContactID and Skills. The table does not have a key.

The NotInList code below is for a subform that consists of a text
field with a control source of ContactID and also a combo box with a
control source of Skills and a row source of Select tblSkills.Skills
ORDER BY tblSkills.

The code below adds a record to the table twice. How can this be
corrected?

Thanks.

Anita

Private Sub cboSkills_NotInList(NewData As String, Response As
Integer)
Dim cnn As ADODB.Connection
Dim rst As ADODB.Recordset
Set cnn = CurrentProject.Connection
Set rst = New ADODB.Recordset

rst.Open Source:="tblSkills", ActiveConnection:=cnn, _
CursorType:=adOpenKeyset, LockType:=adLockPessimistic

If Me.txtContactID > 0 Then
With rst
.AddNew
!ContactID = Me.txtContactID
!Skills = NewData
.Update
End With
Response = acDataErrAdded
Else
Response = acDataErrContinue
MsgBox "Skill was not added to list."
End If

rst.Close
Set rst = Nothing
End Sub