Problem med jquery ajax

CSharp kode 

 [WebMethod]
     public List<objEmployee> GetEmployeesBySkipAndExtend(int skipSize, int extendSize)
     {
         return EmployeeBLL.GetEmployees().Skip(skipSize).Take(extendSize).ToList();
     }

CSharp kode 

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Web.Services;
 using System.Data;
 using System.Data.SqlClient;
 
 /// <summary>
 /// Summary description for WebService
 /// </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 WebService : System.Web.Services.WebService {
 
     public WebService () {
 
         //Uncomment the following line if using designed components 
         //InitializeComponent(); 
     }
 
     [WebMethod]
     public List<objEmployee> GetEmployeesBySkipAndExtend(int skipSize, int extendSize)
     {
         return EmployeeBLL.GetEmployees().Skip(skipSize).Take(extendSize).ToList();
     }
 }

JScript kode 

 function ListExtender(container, extendButton, extendSize) {
     this.container = container;
     this.extButton = extendButton;
 
     this.skipSize = 0;
     this.extendSize = extendSize;
 }
 
 ListExtender.prototype.init = function () {
     $.ajax({
         type: 'get',
         url: 'WebService.asmx/GetEmployeesBySkipAndExtend',
         data: { skipSize: this.skipSize, extendSize: this.extendSize },
         dataType: 'json',
         contentType: "application/json; charset=utf-8",
         success: function (data) {
             $.each(data.d, function (i, item) {
                 var listItem = $('<div></div>', { class: 'row' });
 
                 $('<div></div>', {
                     text: item.Name,
                     class: 'name'
                 }).appendTo(listItem);
 
                 $('<div></div>', {
                     text: item.Age,
                     class: 'age'
                 }).appendTo(listItem);
 
                 $('<div></div>', {
                     text: item.City,
                     class: 'city'
                 }).appendTo(listItem);
 
                 $('<div></div>', {
                     text: item.Sex,
                     class: 'sex'
                 }).appendTo(listItem);
 
                 $('<div></div>', {
                     text: item.PositionID,
                     class: 'position'
                 }).appendTo(listItem);
 
                 listItem.appendTo(this.container);
 
                 this.skipSize += this.extendSize;
             });
         }
     });
 }

JScript kode 

 <script src="js/jquery-1.8.0.min.js" type="text/javascript"></script>
     <script src="js/employeeListExtender.js" type="text/javascript"></script>
     <script type="text/javascript" language="javascript">
         var listExtender = new ListExtender($('#employee-list'), $('#extend-employee-list'), 2);
 
         listExtender.init();
     </script>

Kode 

{"Message":"An attempt was made to call the method \u0027GetEmployeesBySkipAndExtend\u0027 using a GET request, which is not allowed.","StackTrace":"   at System.Web.Script.Services.RestHandler.GetRawParams(WebServiceMethodData methodData, HttpContext context)\r\n   at System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)","ExceptionType":"System.InvalidOperationException"}