Bind dropdown list Jquery Asp.net

In this example we have bind the dropdownlist using jquery ajax in asp.net. In this example I am used the generic hander to get the data from oracle database. Suppose we have table named category its columns categoryId, categoryName

CREATE TABLE Category

(

  PK_CATEGORY_ID   NUMBER,

  CATEGORY_NAME  varchar2(100),

  IS_ACTIVE     varchar(1)

)

I have used generic handler is given below

using System;

using System.Web;

using System.Web.Script.Serialization;

using System.Collections.Generic;

using System.Data;

public class Category : IHttpHandler

{

    public void ProcessRequest(HttpContext context)

    {

           context.Response.ContentType = "application/json";

        context.Response.ContentEncoding = System.Text.Encoding.UTF8;

        Ticket DataAccess = new Ticket();

        int IsuuedId = int.Parse(rq);

        DataTable results = DataAccess.GetCategory(IsuuedId);//get data from  oracle client I have used oracle helper

        // context.Response.Write("{\"eric\":\"12345\"}");

        JavaScriptSerializer serializer = new JavaScriptSerializer();

        List<Dictionary<string, object>> rows = new List<Dictionary<string, object>>();

        Dictionary<string, object> row;

        foreach (DataRow dr in results.Rows)

        {

            row = new Dictionary<string, object>();

            foreach (DataColumn col in results.Columns)

            {

                row.Add(col.ColumnName, dr[col]);

            }

            rows.Add(row);

        }

        context.Response.Write(serializer.Serialize(rows));

        results.Dispose();

    }

    public bool IsReusable

    {

        get

       {

            return false;

        }

    }

}

In aspx page we need the following stuff is given below

<script src="Scripts/jquery1.5.1.min.js" type="text/javascript"></script>

$.ajax({

                        url: 'ajax/Category.ashx',

                        type: 'POST',

                        cache: false,

                        data: jsonData,

                        success: function (data) {

                            $.each(data, function (key, value) {

                               $("#<%=drpCategory.ClientID %>").append($("<option></option>").val(value.CategoryId).html(value.CategoryName));

                            });

                        },

                        error: function (data) {

                            alert("Error occur in applicattion. Please contact Team");

                        }

                    });

<asp:DropDownList id="drpCategory " tabindex="7"  runat="server">

                    </asp:DropDownList>