ComboBox security

Hi, I can encrypt and decrypt with the following codes Edit boxes. How can I do that with ComboBoxes?

// encode form
procedure frmEmployee_OnShow (Sender: string; Action: string);
begin
    frmEmployee.edLastName.Text := Code(frmEmployee.edLastName.Text, KEY_PASSWORD, False);
    frmEmployee.edFistName.Text := Code(frmEmployee.edFistName.Text, KEY_PASSWORD, False);

end;

// decode form
procedure frmEmployee_Button2_OnClick (Sender: string; var Cancel: boolean);
begin
    frmEmployee.edLastName.Text := Code(frmEmployee.edLastName.Text, KEY_PASSWORD, True);
    frmEmployee.edFistName.Text := Code(frmEmployee.edFistName.Text, KEY_PASSWORD, True);
end;