protected function Form_Create()
{
$this->txtValue1 = new QTextBox($this);
$this->txtValue2 = new QTextBox($this);
$this->lstOperation = new QListBox($this);
$this->lstOperation->AddItem('+', 'add');
$this->lstOperation->AddItem('-', 'subtract');
$this->lstOperation->AddItem('*', 'multiply');
$this->lstOperation->AddItem('/', 'divide');
$this->btnCalculate = new QButton($this);
$this->btnCalculate->Text = 'Calculate';
$this->btnCalculate->AddAction(new QClickEvent(), new QServerAction('btnCalculate_Click'));
$this->lblResult = new QLabel($this);
$this->lblResult->HtmlEntities = false;
}