Combo Box Not in list

[Henry]

Private Sub cboByChartNo_NotInList(NewData As String, Response As Integer)

Set db = CurrentDb()
Set rst = db.OpenRecordset("tblPMemberMaster")
rst.AddNew
rst![MemberNumber] = NewData
rst.Update
Response = acDataErrAdded
rst.Close
End Sub

This code puts the new number in tblMemberMaster but the form record is not
synchornized with the table.
I have read lots but can't accomplish the sync without closing and reopening
the form containing the combo box.
No matter what I try, the combo box usage with data not in list is sloppy.
Help would be much appreciated.
BillB