php creating a repeating form

I am trying to create a repeating form that passes variable and updates the table each time the page is submitted.

for example:

<form action="$_SERVER['PHP_SELF']" method="post">
<p>Student Name: <input type="text" name='studentName[]' size='32'></p>


<button type="submit" name='submit' value='submit'>Submit</button>
</form>


<?php  if(isset($_POST['submit']))
{

$studentName[]=$_POST['studentName']; 

?>
<table border='1'>
<tr><th>Students Name</th></tr>


<?php 
for($x=0; $x < count($studentName); $x++)
{
echo "<tr><td>$studentName[$x]</td></tr>";  
} ?>
</table>


}

   ?>

I know that the above code does not work. What would be the correct way to do something like this? Can someone please write me a correct code that does work. I need to see an example.

I searched all over the internet, but I could not find an example.

I thank you in advance.

Best Regards,
Daniel