public void send(String sender_email, String sender_pass, String receiver_email)
        {
            bool        ok = false;
            String      col = "", val = "";
            DataTable   dt   = new DataTable();
            MailMessage mail = new MailMessage();


            mail.From = new MailAddress(sender_email); /// sender of email report
            mail.To.Add(receiver_email);               /// receiver of the email report
            mail.Subject = "Daily Report";
            mail.Body    = "Here is your Sales report of this day " + date_today;

            //https://myaccount.google.com/lesssecureapps?pli=1

            mail.Attachments.Add(new Attachment("\\\\RIGHTAPPS\\RightApps\\BALAI\\101B_cashier_" + export_filename + ".pdf"));

            inc_pbar(10);
            using (SmtpClient smtp = new SmtpClient("smtp.gmail.com", 587))
            {
                smtp.Credentials = new NetworkCredential(sender_email, sender_pass);     // sender email and password
                smtp.EnableSsl   = true;
                try
                {
                    smtp.Send(mail);
                    ok = true;
                }
                catch (Exception ex)
                {
                    ok = false;
                    MessageBox.Show(ex.Message);
                }
            }
            inc_pbar(10);
            String details = " Email Sent to: " + receiver_email + "Time: " + DateTime.Now.ToString("h:mm tt") + " Date: " + DateTime.Now.ToString("yyyy-MM-dd");

            col = "identity,details";
            val = "'" + receiver_email + "','" + details + "'";


            db.InsertOnTable("auto_log", col, val);
        }