a = $a;        $this->b = $b;    }        function __set($d,$e)    {        if($e>0 and $e<100)        {            $this->$d=$e;        }    }    function __get($d)    {        return $this->$d;    }        function he()    {        return $this->a+$this->b;        }    function ji()    {        return $this->a*$this->b;        }        }$c=new jisuan(10,20);echo $c->he();echo "
";echo $c->ji();?>