Error en consulta mysql

Hola, estoy empezando a utilizar mysql y realizando una simple consulta me he atrancado y me salta un error:

 ' BUSCAR OPERARIO
        con.Open()
        Dim sel As String = "SELECT * FROM operarios where Idoperario=?id"
        Dim cn As New MySql.Data.MySqlClient.MySqlCommand(sel, con)
        cm.Parameters.AddWithValue("?id", TextBox1.Text)
        Dim da As New MySql.Data.MySqlClient.MySqlDataAdapter(cm)
        Dim TABLA As New DataTable
        da.Fill(TABLA)
        If TABLA.Rows.Count > 0 Then
            Dim i As Integer
            Dim row As DataRow = TABLA.Rows(0)
            For i = 0 To TABLA.Rows.Count - 1
                ' COGEMOS LA INFORMACION
                NombreoperarioTextBox.Text = (TABLA.Rows(i).Item("Nombreoperario"))
                ApellidosoperarioTextBox.Text = (TABLA.Rows(i).Item("Apellidosoperario"))
                ExtensionTextBox.Text = IIf(row(3) Is DBNull.Value, "", Convert.ToString(row(3)))
            Next
        End If