Oracle Scalar Web Service Problem

My code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data.OracleClient;

namespace AESC
{
    /// <summary>
    /// Summary description for AEService
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
    [System.Web.Script.Services.ScriptService]
    public class AEService : System.Web.Services.WebService
    {
        OracleConnection ra = new OracleConnection("Data Source=;Persist Security Info=True;User ID=;Passwo ...