<?php

class TV
{
protected $model;
private $volume;

public function volumeUp()
{
$this->volume++;
}
public function volumeDown()
{
$this->volume–;
}

public function getModel()
{
return $this->model;
}

public function __construct($m,$v)
{
$this->model=$m;
$this->volume=$v;
}

}

class plazma extends TV {

public function getModel()
{
return $this->model;
}
}
$tv=new plazma(‘abc’,1);
echo $tv->getModel();
?>