private void TXT_LNAME_KeyDown(object sender, KeyEventArgs e)
 {
     if (e.KeyCode == Keys.Enter)
     {
         CMB_GENDER.Focus();
     }
 }
 private void BTN_SAVE_Click(object sender, EventArgs e)
 {
     if (TXT_ID_NUMBER.Text.Length == 0)
     {
         TXT_ID_NUMBER.Focus();
         MSGBOX mdg = new MSGBOX(MessageAlertHeder.Alert(), "PLEASE ENTER ID NO!", MessageAlertImage.Alert());
         mdg.ShowDialog();
     }
     else if (TXT_FNAME.Text.Length == 0)
     {
         TXT_FNAME.Focus();
         MSGBOX mdg = new MSGBOX(MessageAlertHeder.Alert(), "PLEASE ENTER FIRST NAME!", MessageAlertImage.Alert());
         mdg.ShowDialog();
     }
     else if (TXT_LNAME.Text.Length == 0)
     {
         TXT_LNAME.Focus();
         MSGBOX mdg = new MSGBOX(MessageAlertHeder.Alert(), "PLEASE ENTER LAST NAME!", MessageAlertImage.Alert());
         mdg.ShowDialog();
     }
     else if (CMB_GENDER.SelectedIndex == -1)
     {
         CMB_GENDER.Focus();
         MSGBOX mdg = new MSGBOX(MessageAlertHeder.Alert(), "PLEASE SELECT GENDER TYPE!", MessageAlertImage.Alert());
         mdg.ShowDialog();
     }
     else if (CMB_COUNTRY.SelectedIndex == -1)
     {
         CMB_COUNTRY.Focus();
         MSGBOX mdg = new MSGBOX(MessageAlertHeder.Alert(), "PLEASE SELECT COUNTRY!", MessageAlertImage.Alert());
         mdg.ShowDialog();
     }
     else
     {
         groupBox2.Enabled = false;
         SAVE_GUEST();
         groupBox2.Enabled = true;
         BTN_NEW.Focus();
     }
 }