Cascaded dropdown using jQuery

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Text;

/// <summary>
/// Summary description for HimJSON
/// </summary>
public class HimJSON
{
	public HimJSON()
	{
		//
		// TODO: Add constructor logic here
		//
	}

    public static string GetJSONString(DataTable Dt)
    {

        string[] StrDc = new string[Dt.Columns.Count];
        string HeadStr = string.Empty;

        for (int i = 0; i < Dt.Columns.Count; i++)
        {

            StrDc[i] = Dt.Columns[i].Caption;

            HeadStr += "\"" + StrDc[i] + "\" : \"" + StrDc[i] + i.ToString() + "¾" + "\",";
        }

        HeadStr = HeadStr.Substring(0, HeadStr.Length - 1);

        StringBuilder Sb = new StringBuilder();
        Sb.Append("{\"" + Dt.TableName + "\" : [");

        for (int i = 0; i < Dt.Rows.Count; i++)
        {

            string TempStr = HeadStr;
            Sb.Append("{");

            for (int j = 0; j < Dt.Columns.Count; j++)
            {

                TempStr = TempStr.Replace(Dt.Columns[j] + j.ToString() + "¾", Dt.Rows[i][j].ToString());
            }

            Sb.Append(TempStr + "},");
        }

        Sb = new StringBuilder(Sb.ToString().Substring(0, Sb.ToString().Length - 1));
        Sb.Append("]};");

        return Sb.ToString();
    }


}