Moderators, if this should go into another forum that is more appropriate, please feel free to place it there.

I've seen a lot of examples of how to export data into an Excel spreadsheet using ASP.NET and most have been wrong.
This code works and is very simple to follow.
This is my first contribution to the forums, enjoy...Paul

// these namespaces need to be added to your code behind file
using System.Configuration;
using System.Data.SqlClient;
using System.Data;

namespace MySpot.UserPages
{
    public partial class Journal : System.Web.UI.Page
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["MySpotDBConnStr"].ConnectionString);
        DataTable dt = new DataTable();
       
        // regular page_load from .aspx file
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
            }
        }

        // added a button with ID=btnDownload and double clicked it's onclick event to auto create method
        protected void btnDownload_Click(object sender, EventArgs e)
        {
            string queryStr = "SELECT * from table";
            SqlDataAdapter sda = new SqlDataAdapter(queryStr, conn);
            sda.Fill(dt);
            ExportTableData(dt);
        }

        // this does all the work to export to excel
        public void ExportTableData(DataTable dtdata)
        {
            string attach = "attachment;filename=journal.xls";
            Response.ClearContent();
            Response.AddHeader("content-disposition", attach);
            Response.ContentType = "application/ms-excel";
            if (dtdata != null)
            {
                foreach (DataColumn dc in dtdata.Columns)
                {
                    Response.Write(dc.ColumnName + "\t");
                    //sep = ";";
                }
                Response.Write(System.Environment.NewLine);
                foreach (DataRow dr in dtdata.Rows)
                {
                    for (int i = 0; i < dtdata.Columns.Count; i++)
                    {
                        Response.Write(dr[i].ToString() + "\t");
                    }
                    Response.Write("\n");
                }
                Response.End();
            }
        }
    }
}

In IE9 the regular bar comes on down at the bottom asking to save or open, just click open and there it is
In FireFox that pesky download box comes on, then pops up a dialog, click open and there it is
in Opera it asks to save or open, click open and there it is.