Filtering using binding source

Just wondering why my following code is clearing all records instead of filtering proprerly by last name, do I have the syntax right? thanks fkor assistance

Code:

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Private Sub txtLastName_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtLastName.TextChanged


        Dim strFilterLastName As String = Me.txtLastName.Text
        Me.TblAddressesBindingSource.Filter = "fldLastName ='" & strFilterLastName & "'"

    End Sub

    Private Sub frmFind_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        TblAddressesTableAdapter.Fill(Me.AddressbookDataSet.tblAddresses)

    End Sub

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