Sqlserver vers excel

 protected void Button1_Click(object sender, EventArgs e)
    {   SqlConnection cn= new SqlConnection(@"..");

        cn.Open();
    
        SqlDataAdapter da = new SqlDataAdapter(@"Dselect * from Article ", cn);
        DataTable dt = new DataTable();
        da.Fill(dt);
        cn.Close();

        string attachment = "attachment; filename=Employee.xls";

        Response.ClearContent();

        Response.AddHeader("content-disposition", attachment);

        Response.ContentType = "application/vnd.ms-excel";

        string tab = "";

        foreach (DataColumn dc in dt.Columns)

        {

            Response.Write(tab + dc.ColumnName);

            tab = "\t";

        }

        Response.Write("\n");

        int i;

        foreach (DataRow dr in dt.Rows)

        {

            tab = "";

            for (i = 0; i < dt.Columns.Count; i++)

            {

                Response.Write(tab + dr[i].ToString());

                tab = "\t";

            }

            Response.Write("\n");

        }

        Response.End();

    }