上次访问页面（COOKIE）和php中当前搜索页面的逻辑错误

Question

I have a page ( index.php ) where i display latest events fetched from db and a search box on the top of page, if someone search any event then all events regarding search displayed with name and link on page . now what i need

1. if we search some event and go to that event page and come back (index.php) then last search result should be displayed...right now if i go back then display latest event.
2. if we go to specific event and close browser at that time ( or go back and close ) and if open that site again i need to display last visited event page link on index.php
3. if we first time come to page ( or after cookie expire) then all latest events ( right now only 4 latest event)should display.

4. if we search and that is not found then display "NO event found" and request to search again.

   currently point 2 and point 4 is covered successfully, but point 3 is not done, please suggest my logical conditions in proper way and also suggest what do i do for point 1

below if main code of my page

index.php

<form action="<?=$_SERVER['PHP_SELF'];?>" method="get" accept-charset="utf-8">              
    <input type="text"  name="keyword" id="keyword"  placeholder="Search for Event" value="">           
    <input type="submit" name="submit" id="submit" value="Search" >     
</form>

if(empty($_GET['keyword']) && !isset($_SERVER['HTTP_REFERER'])) {
   if(!empty($_COOKIE['LAST_EVENT_ID'])) { ?>
       <div class="module list">
        <ul id="people">
            <li>
            <a href="eventinfo.php?evt_id=<?=$_COOKIE['LAST_EVENT_ID'];?>&evt_name=<?=$_COOKIE['LAST_VISITED_EVENT'];?>">           
            <h2><?=$_COOKIE['LAST_VISITED_EVENT']?></h2>                    
                </a>
            </li>
         </ul>
       </div>
<?php } } 
// Note count($eventItems)==4 ( by default latest events)       
    else if(count($eventItems) == 0) { ?>       
       <h2>No Events found, please Search again</h2>
<?php } 
      else { 
 ?> 
     <div class="module list">
     <ul id="people">
<?php    foreach($eventItems as $value) { ?>
         <li>
            <a href="eventinfo.php?evt_id=<?=$value->event_id?>&evt_name=<?=$value->name?>">            
            <h2><?=$value->name?></h2>                  
            </a>
         </li>          
 <?php      } ?> 
   </ul>
  </div>

eventinfo.php

<?php ob_start();
$evt_id=$_GET['evt_id'];
$evt_name=$_GET['evt_name'];
define('SITE_PATH','http://localhost/hello_world/');    
define('EVENT_ID',$evt_id);
/* first remove old cookie value */
//setcookie("LAST_EVENT_ID",EVENT_ID, time()-3600*24*7);
//setcookie("LAST_VISITED_EVENT", $evt_name, time()-3600*24*7);

setcookie("LAST_EVENT_ID", EVENT_ID, time()+3600*24*7);
setcookie("LAST_VISITED_EVENT", $evt_name, time()+3600*24*7);

if (is_dir($evt_name)){
    header("location:".EVENT_PATH);
}
else{
    header("location:event_detail.php");
}


?>

please tell me how do i modify my if else condition to fulfill all above points

Thanks

UPDATE

i also create truth table for all situation, plz help me to develop logic.. here is the link for truth table

Answer 1

Change

<li>
    <a href="eventinfo.php?evt_id=<?=$_COOKIE['LAST_EVENT_ID'];?>&evt_name=<?=$lastEventDetail['name'];?>">         
        <h2><?=$lastEventDetail['name']?></h2>                  
    </a>
</li>

to

<li>
    <a href="eventinfo.php?evt_id=<?=$_COOKIE['LAST_EVENT_ID'];?>&evt_name=<?=$_COOKIE['LAST_VISITED_EVENT'];?>">         
        <h2><?=$_COOKIE['LAST_VISITED_EVENT']; ?></h2>                  
    </a>
</li>

Their is no value for $lastEventDetail['name'] .. the last event name is in the cookie