Open excel sheet after button click

protected void cmdexcelsheetupload_Click(object sender, EventArgs e)
    {
        {


            {
                string strExcelPath = "";

                AllUtilities.ImageUtilities oIU = new AllUtilities.ImageUtilities();
                try
                {

                    if (txtFile.HasFile)
                        strExcelPath = txtFile.PostedFile.FileName.Trim();
                    string strNewFilename = strExcelPath.ToString();
                    strNewFilename = oIU.ExtractFilename(strNewFilename);
                    string strSaveLocation = Server.MapPath("../Excelsheet/") + strNewFilename;
                    txtFile.SaveAs(strSaveLocation);
                    string path = Server.MapPath("../Excelsheet/3ymmember.xls");
                    // Connection String to Excel Workbook
                    //string excelConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=D:\demo.xlsx; Extended Properties=""Excel 12.0; HDR=YES;""";
                    string excelConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + path + ";" + @"Extended Properties=""Excel 8.0;HDR=Yes"";";
                    // Create Connection to Excel Workbook
                    using (OleDbConnection connection = new OleDbConnection(excelConnectionString))
                    {
                        //OleDbCommand command = new OleDbCommand("Select CAdminLoginId='"+ strCorporateAdmin +"', CUserLoginId, CUserPassword, FirstName, LastName, EmailId, Status FROM [demo$]", connection);
                        OleDbCommand command = new OleDbCommand("Select Name, Address,ContactNo,Email,MemDetail,Reg_No,startDate,endDate FROM [3ymmember$]", connection);
                        connection.Open();

                        if (RadioButtonList1.SelectedIndex == 0)
                        {
                            // Create DbDataReader to Data Worksheet
                            using (DbDataReader dr = command.ExecuteReader())
                            {
                                // SQL Server Connection String
                                string sqlConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
                                // Bulk Copy to SQL Server
                                using (SqlBulkCopy bulkCopy = new SqlBulkCopy(sqlConnectionString))
                                {
                                    bulkCopy.DestinationTableName = "CommiteeMemberFull";
                                    bulkCopy.WriteToServer(dr);
                                    Label1.Text = "Users has been added successfully.";
                                }
                            }


                        }
                        else if (RadioButtonList1.SelectedIndex == 1)
                        {

                            OleDbDataReader odr = command.ExecuteReader();
                            string Name = "";
                            string Address = "";
                            string ContactNo = "";
                            string Email = "";
                            string MemDetail = "";
                            string Reg_No = "";
                            string startDate = "";
                            string endDate = "";
                            while (odr.Read())
                            {
                                Name = valid(odr, 0);//Here we are calling the valid method
                                Address = valid(odr, 1);
                                ContactNo = valid(odr, 2);
                                Email = valid(odr, 3);
                                MemDetail = valid(odr, 4);
                                Reg_No = valid(odr, 5);
                                //Here using this method we are inserting the data into the database
                                insertdataintosql(Name, Address, ContactNo, Email, MemDetail, Reg_No,startDate, endDate);
                            }
                            connection.Close();


                        }

                        else
                        {
                            Label1.Text = "Please Select One Opration!";
                        }
                    }

                }
                catch (Exception ex)
                {
                    Label1.Text = ex.Message;
                    // lblMessage.Text = "There were some problem with update. Please be sure that xls file in proper format and not uploading xls file containing already exiting user name in database.";
                }
                finally
                {
                    Label1.Visible = true;


                }

            }
        }

    }

 public void insertdataintosql(string Name, string Address, string ContactNo, string Email, string MemDetail, string Reg_No, string startDate, string endDate)
    {//inserting data into the Sql Server
        string sqlConnectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        SqlConnection connection = new SqlConnection(sqlConnectionString);
        // SqlConnection conn = new SqlConnection("Data Source=.\\sqlexpress;AttachDbFileName=|DataDirectory|exceltosql.mdf;Trusted_Connection=yes");
        SqlCommand cmd = new SqlCommand();

        cmd.CommandText = "Update CommiteeMemberFull SET Name=@Name, Address=@Address,ContactNo=@ContactNo,Email=@Email,MemDetail=MemDetail ,startDate=startDate,endDate=endDate where Reg_No=@Reg_No";

        cmd.Parameters.Add("@Name", SqlDbType.NVarChar).Value = Name;
        cmd.Parameters.Add("@Address", SqlDbType.NVarChar).Value = Address;
        cmd.Parameters.Add("@ContactNo", SqlDbType.NVarChar).Value = ContactNo;
        cmd.Parameters.Add("@Email", SqlDbType.NVarChar).Value = Email;
        cmd.Parameters.Add("@MemDetail", SqlDbType.NVarChar).Value = MemDetail;
        cmd.Parameters.Add("@Reg_No", SqlDbType.NVarChar).Value = Reg_No;
        cmd.Parameters.Add("@startDate", SqlDbType.NVarChar).Value = startDate;
        cmd.Parameters.Add("@endDate", SqlDbType.NVarChar).Value = endDate;

        cmd.CommandType = CommandType.Text;
        connection.Open();
        cmd.Connection = connection;
        cmd.ExecuteNonQuery();
        connection.Close();
        Label1.Text = "Excel Sheet Updated successfuly!";
    }
    protected string valid(OleDbDataReader myreader, int stval)//if any columns are 
    //found null then they are replaced by zero
    {
        object val = myreader[stval];
        if (val != DBNull.Value)
            return val.ToString();
        else
            return Convert.ToString(0);
    }<pre>

<pre lang="cs">private string ReturnExtension(string fileExtension)
  {
      switch (fileExtension)
      {
          case ".htm":
          case ".html":
          case ".log":
              return "text/HTML";
          case ".txt":
              return "text/plain";
          case ".doc":
              return "application/ms-word";
          case ".tiff":
          case ".tif":
              return "image/tiff";
          case ".asf":
              return "video/x-ms-asf";
          case ".avi":
              return "video/avi";
          case ".zip":
              return "application/zip";
          case ".xls":
          case ".csv":
              return "application/vnd.ms-excel";
          case ".gif":
              return "image/gif";
          case ".jpg":
          case "jpeg":
              return "image/jpeg";
          case ".bmp":
              return "image/bmp";
          case ".wav":
              return "audio/wav";
          case ".mp3":
              return "audio/mpeg3";
          case ".mpg":
          case "mpeg":
              return "video/mpeg";
          case ".rtf":
              return "application/rtf";
          case ".asp":
              return "text/asp";
          case ".pdf":
              return "application/pdf";
          case ".fdf":
              return "application/vnd.fdf";
          case ".ppt":
              return "application/mspowerpoint";
          case ".dwg":
              return "image/vnd.dwg";
          case ".msg":
              return "application/msoutlook";
          case ".xml":
          case ".sdxl":
              return "application/xml";
          case ".xdp":
              return "application/vnd.adobe.xdp+xml";
          default:
              return "application/octet-stream";
      }
  }