hi friends,
 I have written the code as below for sorting the datagrid columns.but its not working.please check the code and help me to overcome my problem..
************************************************** *****************
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace WebApplication1.images
{
        public class sort : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.DataGrid DataGrid1;

        private void Page_Load(object sender, System.EventArgs e)
        {

            if (!Page.IsPostBack )

            {

                BindGrid();

            }
        }

        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        public void DataGrid_Page(object sender, DataGridPageChangedEventArgs e)
        {
            DataGrid1.CurrentPageIndex = e.NewPageIndex;
            BindGrid();
        }

        public void DataGrid_Sort(object sender, DataGridSortCommandEventArgs e)
        {
DataGrid1.CurrentPageIndex = 0;
            SortField = e.SortExpression;
            BindGrid();



        }

        protected String SortField
        {
            get
            {
                object o = ViewState["SortField"];
                return (o == null) ? String.Empty : (String)o;
            }
            set
            {
                ViewState["SortField"] = value;
            }
        }
        void BindGrid()
        {
            SqlConnection con3=new SqlConnection("server=localhost;Persist Security Info=False;User ID=sa;password=sa;Initial Catalog=vms_database;Data Source=server0");
            string CommandText;
            if(SortField == String.Empty)
                CommandText = "select * from Admin_ringtone order by songname";
            else
                CommandText = "select * from Admin_ringtone order by" + SortField;
            SqlDataAdapter ad = new SqlDataAdapter("select * from Admin_ringtone ",con3);
            DataSet ds = new DataSet();
            ad.Fill(ds,"Admin_ringtone");
            DataGrid1.DataSource = ds;
            DataGrid1.DataBind();

        }
    }
}

__________________
sumith