Session values not clearing

I think this may be something with my local test environment as I had a problem like this before but when I put it up on the live host it worked (I don't have hosting for this site yet). I can not get my session values to clear. Here is the code I have:

<?php
if (isset($_POST["logoutButton"])){
// WA_ClearSession
$clearAll = TRUE;
$clearThese = explode(",","");
if($clearAll){
foreach ($_SESSION as $key => $value){
unset($_SESSION[$key]);
}
}
else{
foreach($clearThese as $value){
unset($_SESSION[$value]);
}
}
}
?>

Assuming there is a logoutButton form element on the page, I dont see a problem with the code.

I would use a hidden form element for the log out trigger to get around an IE bug where the submit button is sometimes not sent with the form:

<form id="form1" method="post" action="logout.php">
  <strong>
  <input name="logoutButton" type="hidden" id="logoutButton" value="Log Out" />
  </strong>
  <label>
    <input type="submit" name="button" id="button" value="Log Out" />
  </label>
</form>

and add the clear session value to the logout.php page.

Ah-ha. I forgot to place the action on the form so it wasn't posting anywhere. Duh.