Tab 1
number of buttons = 2
$VAR1 = [
          {
            'parent' => '-1',
            'y_coordinate' => '5',
            'x_coordinate' => '5',
            'evt_1_function' => 'testclick',
            'x_size' => '-1',
            'evt_1' => 'EVT_BUTTON',
            'internal_name' => 'test1',
            'text' => 'button 1',
            'y_size' => '-1'
          }
        ];
$VAR1 = [
          {
            'parent' => '-1',
            'y_coordinate' => '50',
            'x_coordinate' => '50',
            'evt_1_function' => 'testclick2',
            'x_size' => '-1',
            'evt_1' => 'EVT_BUTTON',
            'internal_name' => 'test2',
            'text' => 'button 2',
            'y_size' => '-1'
          }
        ];

Tab 2
number of buttons = 0