How to set a session variable when clicking a link

I have the following problem… I want to set a session variable when clicking on a normal link like:

<a href="home" name="home">home</a>

My research seems to point out that it is not possible for PHP to catch up with the click event in a such a way that it would set a session variable.

I believe it is possible with Ajax, but how? And what would my link look like?
Setting the session variable should look like:

$_SESSION['link'] = home;

So in short: When clicking on a link in HTML, a session variable must be set.
HOW am i going to do that?

PS: I’m not quite familiar with Ajax, but I’ll catch up.

EDIT: The links will refer to the same page, also i want to avoid urls like “home.php?link=X”.
If it isn’t possible to do it any other way, too bad. But I’ll hope there is a solution.
Important: the name of the link will be the value of $_SESSION['link']

Answer

    session_start();
    if(isset($_SESSION['current'])){
         $_SESSION['oldlink']=$_SESSION['current'];
    }else{
         $_SESSION['oldlink']='no previous page';
    }
    $_SESSION['current']=$_SERVER['PHP_SELF'];

Maybe this is what you’re looking for? It will remember the old link/page you’re coming from (within your website).

Put that piece on top of each page.

If you want to make it ‘refresh proof’ you can add another check:

   if(isset($_SESSION['current']) && $_SESSION['current']!=$_SERVER['PHP_SELF'])

This will make the page not remember itself.

UPDATE: Almost the same as @Brandon though… Just use a php variable, I know this looks like a security risk, but when done correct it isn’t.

 <a href="home.php?a=register">Register Now!</a>

PHP:

 if(isset($_GET['a']) /*you can validate the link here*/){
    $_SESSION['link']=$_GET['a'];
 }

Why even store the GET in a session? Just use it. Please tell me why you do not want to use GET. « Validate for more security. I maybe can help you with a better script.