belajar oop php

<?php

class box{
        function displaybox(){
            ?>
            <div class="box">
            <?php

        }
}
class CLbox extends box{
        function closebox(){
        ?>
        </div>
        <?php
        }
        }

class form{
    var $fields     = array();
    var $totFields  = 0;
    var $thisname="default";


        function __construct(){
            $this->asend = "send.php";
            $this->amethod = "post";
        }
        function change_form($thisname,$thisaction,$thisMethod){
            $this->asend = $thisaction;
            $this->amethod = $thisMethod;
            $this->thisname = $thisname;
        }

        function displayform(){
            ?>
            <form action="<?php print $this->asend;?>" name="<?php print $this->thisname;?>" method="<?php print $this->amethod;?>">
            <?php
            for($op=0; $op<count($this->fields);$op++){
            ?>
            <label><?php print $this->fields[$op]['labelField'];?></label>
            <input type="<?php print $this->fields[$op]['typeField'];?>" name="<?php print $this->fields[$op]['nameField'];?>"/>
            <?php
            }
        }
        function addField($typeField,$nameField,$labelField){
            $this->fields[$this->totFields]['typeField']=$typeField;
            $this->fields[$this->totFields]['nameField']=$nameField;
            $this->fields[$this->totFields]['labelField']=$labelField;
            $this->totFields++;
        }
}
class createButton extends form{
        function showButton($typeButton,$valButton){
        $this->valB=$valButton;
        $this->typeB=$typeButton;
        ?>
        <input type="<?php print $this->typeB;?>" name="nama" value="<?php print $this->valB;?>"/>
        <?php
        }

        }

class closeF extends form{
        function closeform(){
        ?>
        </form>
        <?php
        }
        }


$createbox = new box();
$showForm = new form();
$clsBox = new CLbox();
$cls = new closeF;
$BTton = new createButton;
?>

<html>
<body>
<?php
$acc=$_SERVER["PHP_SELF"];
$createbox->displaybox();
$showForm->change_form("nameform","$acc","post");
$showForm ->addField("text","name","label");
$showForm ->addField("radio","name","radio");
$showForm->displayform();
$BTton->showButton("submit","new");
$BTton->showButton("reset","reset");
$cls->closeform();
?>
</body>
</html>