private void cAreaTextBox_KeyDown(object sender, KeyEventArgs e)
 {
     if (e.KeyCode == Keys.Enter)
     {
         LandmarktextBox.Focus();
         e.Handled = true;
     }
 }
 public void ResetCorporateAddress()
 {
     cFlatNoTextBox.Clear();
     cHouseNoTextBox.Clear();
     cRoadNoTextBox.Clear();
     blocktextBox.Clear();
     cAreaTextBox.Clear();
     cContactNoTextBox.Clear();
     LandmarktextBox.Clear();
     cPostCodeTextBox.Clear();
     cPostOfficeCombo.SelectedIndex = -1;
     cThanaCombo.SelectedIndex      = -1;
     cDistCombo.SelectedIndex       = -1;
     cDivisionCombo.SelectedIndex   = -1;
 }