How to backup data from database in SqlExpress

private void DatabaseBackup()
        {
            string strDate = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString().PadLeft(2, '0') + DateTime.Now.Day.ToString().PadLeft(2, '0');
            string[] strTime = DateTime.Now.TimeOfDay.ToString().Split(':');
            string strDateTime = strDate + " " + strTime[0].PadLeft(2, '0') + strTime[1].PadLeft(2, '0');
            try
            {
                string backupPath = txtBackupLocation.Text.Trim() + "\\" + strDateTime + ".bak";
                int retVal = 0;
                retVal = _settingManager.DatabaseBackup(backupPath);
                if (retVal != 0)
                {
                    btnBackupDatabase.Enabled = false;
                    lblBackupStatus.Text = "Database backup successful.";
                    MessageBox.Show("The backup of database completed successfully." + Environment.NewLine + backupPath, Program.MESSAGEBOXTITLE, MessageBoxButtons.OK, MessageBoxIcon.Warning);
                    btnClose.Focus();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error [Database Backup]: " + Environment.NewLine + ex.Message, Program.MESSAGEBOXTITLE, MessageBoxButtons.OK, MessageBoxIcon.Error);
                lblBackupStatus.Text = "Database backup failed.";
            }
        }