C#

using System;
using System.Drawing;
using System.Windows.Forms;


    public partial class Form1 : Form
    {
        public Button sb;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            for (int x = 0; x < 10; x++)
            {
                sb = new Button();
                sb.Size = new Size(25, 25);
                sb.Location = new Point(x * 25, 10);
                sb.Visible = true;
                sb.Text = x.ToString();
                sb.Click += new EventHandler(sb_Click);
                Controls.Add(sb);
            }
        }

        private void sb_Click(object sender, System.EventArgs e)
        {
            Button sb = sender as Button;
            this.Text = sb.Text;
        }
    }

Response.Clear(); 
Response.AddHeader("content-disposition", "attachment;filename=FileName.xls");
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = "application/vnd.xls";
System.IO.StringWriter stringWrite = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
myDataGrid.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.End();