如何使用asp.net中的post方法制作Web服务？

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web .Script .Serialization;

namespace ReturnJSONandXML
{
    /// <summary>
    /// Summary description for service
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // 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 service : System.Web.Services.WebService
    {


        [WebMethod]
        public string GetcompaniesJSON()
        {

            companies[] COMP = new companies[]{
                new companies ()
                {
                    companytid ="C123",
                    companynm ="TCS"
                },
                 new companies ()
                {
                    companytid ="C1234",
                    companynm ="wipro"
                }
            };

            return new JavaScriptSerializer().Serialize(COMP);


        }

    }
}

我正在使用此代码。
请告诉我如何制作纯发布方法Web服务以及如何在客户端调用它？
这段代码提供了这种类型的输出

<string xmlns="http://tempuri.org/">
[{"companytid":"C123","companynm":"TCS"},{"companytid":"C1234","companynm":"wipro"}]
</string>