.net command application export data to excel

  public static void ExportToExcel(System.Data.DataTable dt, string excelFilePath = null)
        {
          //  string FileName = "Test.xls";
            string fullpath = excelFilePath;

            int tblborder = 2;
            StreamWriter SW;
            SW = File.CreateText(fullpath);
            StringBuilder objSB = new StringBuilder();
            objSB.Append("<Table border=" + tblborder + "  width=100%>");

            objSB.Append("<tr>");

            for (int i = 0; i < dt.Columns.Count; i++)
            {
                objSB.Append("<th valign=middle>" + dt.Columns[i].ColumnName + "</th>");
            }

            objSB.Append("</tr>");
            objSB.Append("<tr>");

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    objSB.Append("<tr>");
                    objSB.Append("<td align=center>" + dt.Rows[i][j].ToString() + "</td>");
                    objSB.Append("</tr>");
                }
            }

            objSB.Append("</Table>");
            SW.Write(objSB.ToString());
            SW.Close();
          //  Response.Redirect(filePath);



        }