//  If you are using a CAS secured folder via SSL (i.e. https), use the 
//  cookie name of MOD_AUTH_CAS_S, otherwise just use MOD_AUTH_CAS:

//  Set the PATH to the path of the secure folder being used
$PATH = '/first_folder/secure_folder';

//  Example:  
//   Your URL is https://web2.uconn.edu/dogs/admin
//     Then COOKIE_NAME is MOD_AUTH_CAS_S, and PATH is /dogs/admin

setcookie($COOKIE_NAME, '', time()-1000, $PATH);

//  Set location of CAS logout page.  The Javascript below will
//  redirect the browser to this page.
$DESTINATION = "https://login.uconn.edu/cas/logout";

<script language=javascript>
location="<?php echo $DESTINATION?>"
Click <a href="<?php echo $DESTINATION?>">here</a> to goto to 
<b>logout from CAS</b>.