AJAX 和WebService 现实多个DropdownList联动

1：前台jquery代码

        //根据部门 获取员工姓名
        function GetEmployeeName() {
            var gid = $("# MdDepartment_ParentID");
            var gpid = $("#HrEmployee_EmployeeName");
            $("#HrEmployee_EmployeeName option").remove(); // 先删除所有项，以便重新加载 
            gpid.append("<option value=''>--- 请选择 ---</option>"); //默认项
            $.ajax({
                type: "Post",
                url: "Edit.aspx/getEmployeeName",
                data: "{'DepartmentID':'" + gid.val() + "'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    var arrayChar = data.d;
                    for (var index in arrayChar) {
                        if (typeof arrayChar[index] != 'undefined' && typeof arrayChar[index] != 'function') {
                            var info = arrayChar[index];
                            gpid.append($("<option></option>").val(info.ID).html(info.EmployeeName));
                        }
                    }
                },
                error: function (err) {
                }
            });
        }

        //获取员工工号
        function GetWorkNumInfo() {

            var gid = $("#HrEmployee_EmployeeName");
            var ms = $("#HrEmployee_WorkNo");
            $.ajax({
                type: "Post",
                url: "Edit.aspx/GetWorkNumInfo",
                data: "{'ID':'" + gid.val() + "'}",
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    var arrayObj = data.d.toString().split(",");
                    ms.val(arrayObj[0]);
                },
                error: function (err) {
                    //alert(err);
                }
            });
                  }

2：后台代码.cs

 [System.Web.Services.WebMethod]
    public static List<string> GetWorkNumInfo(string ID)
    {
        List<string> list = new List<string>();
        HrEmployee bll = new HrEmployee();
        HrEmployeeInfo info = bll.GetModel(ID);
        if (info != null)
        {
            list.Add(info.WorkNo);
        }
        return list;
    }

    [System.Web.Services.WebMethod]
    public static List<HrEmployeeInfo> getEmployeeName(string DepartmentID)
    {
        HrEmployee bll = new HrEmployee();
        List<DBParameter> dbParameters = new List<DBParameter>();
        dbParameters.Add(new DBParameter("@DepartmentID", DepartmentID));
        List<HrEmployeeInfo> list = bll.GetList("", "DepartmentID=@DepartmentID", "", dbParameters);
        return list;
    }

注：HrEmployeeInfo 为实体类 希望大家能够看懂