用Access数据库，ADO怎样实现密码登陆呀？？？

Question

adoquery.sql.clear;
adoquery.sql.add('select * from user where    
  username="'+Dbcombobox1.text+'"');
adoquery.open;
if Edit1.text=adoquery1.fieldbyname('password').asstring then
  form2.showmodal;
else
begin
  showmessage('密码错误');
  application.terminate;
end;
  

Answer 1

procedure TForm1.FormCreate(Sender: TObject);
begin
  ADOQuery.SQL.Text:='select username,password from password';
  ADOQuery.ExecSQL;end;procedure TForm1.Button1Click(Sender: TObject);
begin
  if ADOQuery.FieldByName('password').AsString=Edit1.Text then
    Form2.Show
  else
    Close;
end;

Answer 2

怎样才能把表中的用户名显示在dbcombobox1 中？？