Hente oplysninger i en anden tabel med en fremmednøgle

Jeg har følgende kode:

        Dim con As SqlConnection = New SqlConnection("server=MFFUTURA;Integrated Security=SSPI;database=F9999")
        con.Open()
        Dim cmd As SqlCommand = New SqlCommand("SELECT * FROM ord WHERE free4<>1", con)
        Dim rdr As SqlDataReader = cmd.ExecuteReader
        While rdr.Read
            kundenr = CType(rdr(4), String)
            Dim cmd2 As SqlCommand = New SqlCommand("SELECT * FROM actor WHERE custno=" & kundenr, con)
            Dim rdr2 As SqlDataReader = cmd2.ExecuteReader
            Ordrenr = CType(rdr(0), String)
            Ordredato = CType(rdr(3), String)
            Forventetreturdato = CType(rdr(123), String)
            afdnr = CType(rdr2(99), String)
            Kundenavn = CType(rdr(5), String)
            Adresse1 = CType(rdr(6), String)
            Adresse2 = CType(rdr(7), String)
            Postnr = CType(rdr(10), String)
            By = CType(rdr(11), String)
            Ubernahmescheinnr = CType(rdr(24), String)
            gr2 = CType(rdr(19), String)
            Dim cmd3 As SqlCommand = New SqlCommand("SELECT * FROM txt WHERE Lang=49 AND TxtTp=49 AND TxtNo=" & gr2, con)
            Dim rdr3 As SqlDataReader = cmd2.ExecuteReader
            leveringsadresseforcontaineren = CType(rdr3(4), String)
            tekst = Ordrenr & ", " & Ordredato & ", " & Forventetreturdato & ", " & afdnr & ", " & Kundenavn & ", " & Adresse1 & ", " & Adresse2 & ", " & Postnr & ", " & By & ", " & Ubernahmescheinnr & ", " & leveringsadresseforcontaineren & ", " & Sdato & ", " & Stid
            ListBox1.Items.Add(tekst)
        End While
        con.Close()

Mit program går i fejl ved linien:

Dim rdr2 As SqlDataReader = cmd2.ExecuteReader

Med denne fejlmeddelelse:

An unhandled exception of type 'System.InvalidOperationException' occurred in system.data.dll

Additional information: There is already an open DataReader associated with this Connection which must be closed first.

Er der nogle der kan se hvad der er galt?