when using ADO and stored procedures with parameters, you want to use the
ADO command object. Please see the MSDN ADO reference for details. Here's
how you could modify your code:

    Dim cn As ADODB.Connection
    Dim co As ADODB.Command
    Dim params(3) As ADODB.Parameter

    Dim s As String

    Set cn = New ADODB.Connection
    Set co = New ADODB.Command

    cn.Open "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security
Info=False;Initial Catalog=Address"

    Set co.ActiveConnection = cn

    Set params(0) = co.CreateParameter("CustomerID", adInteger,
adParamInput, , 1)
    co.Parameters.Append params(0)
    Set params(1) = co.CreateParameter("CustomerName", adChar, adParamInput,
10, "Peter Miller")
    co.Parameters.Append params(1)
    Set params(2) = co.CreateParameter("AreaCode", adChar, adParamInput, 10,
Null)
    co.Parameters.Append params(2)

    co.CommandText = "UpdateCustomer"
    co.CommandType = adCmdStoredProc

    co.Execute

    cn.Close

This would call the following SP:

CREATE PROCEDURE UpdateCustomer



 AS
 SET NOCOUNT ON

The ADO command object provides better capabilities to call stored
procedures with both input and output parameters. It requires a bit more
coding, though.

Regards,
Uwe Baumann