My cookie seems to be working but I just noticed that there is a fault

My cookie seems to be working but I just noticed that there is a fault in my code. I'm not sure what is correct.

I had two values in there at one point "kw" and "aid". Then I took one of them out. The "kw" seems to be working but I see that "aid" is still in my code.

# Set the keyword cookie with only alpha numeric and limit length
function alphanumericAndSpace( $string )
    {
$length = 80;
return substr (preg_replace('/[^a-zA-Z0-9\s]/', '', $string),0,$length);
    }
if (isset($_GET['kw']))
  {
  setcookie('keyword', alphanumericAndSpace($_GET['kw']), time()+365*60*24*60);
  $aid = alphanumericAndSpace($_GET['kw']);
  }
if (isset($_COOKIE['keyword']))
  {
  $kw = alphanumericAndSpace($_COOKIE['keyword']);
  }
  

Code (markup):

Could anyone explain how this code works and or help me clean it up please?

Thanks

Mike

ps "aid" was "affiliateid" but I could not get the two cookie values to work. If I could get them both to work that would be cool.

 

this is php. post it there.