使用PHP，HTML-CSS在同一页面的其他分区中显示结果

I am newbie to HTML-CSS and PHP. Here I am creating my own web-page in which I want to give hyperlink which should later be shown result in other division of same page, say result as more checkboxes for other options in other division of same page. How can get which option from the following hyperlinks has been clicked and how to process it further in PHP for getting desired result:

Below is my PHP snippet for it:

  <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">

    <a href="" target="_blank">CT1<br></a>
    <a href="" target="_blank">CT2<br></a>      
    <a href="" target="_blank">CT3<br></a>
    <a href="" target="_blank">CT4<br></a>