private void btnSendMail_Click(object sender, EventArgs e)
 {
     ReceptionTaskBO aReceptionTaskBO = new ReceptionTaskBO();
        string SendEmail = CORE.CONSTANTS.ListEmails.SenderMail.ID;
        string Pass = CORE.CONSTANTS.ListEmails.SenderMail.PassWord;
        string ReceiveEmail = CORE.CONSTANTS.ListEmails.ReceiverMail1.ID;
        string subject = "Gửi thông báo tạm trú ngày :" + String.Format("{0:MM-dd-yyyy}", DateTime.Now);
        string filename = this.FileName;
        aReceptionTaskBO.SendMail(SendEmail, Pass, ReceiveEmail, subject, filename);
        MessageBox.Show("Gửi Email thành công", "Thông báo", MessageBoxButtons.OK, MessageBoxIcon.Information);
 }