title: unsetting cookie getting Undefined index
body: <p>test.php</p>
  
  <pre><code>&lt;?php
  setcookie('username', 'mary', time()+1000);
  
  
  setcookie('username', 'mary', time()-1000);
  
  
   ?&gt;
  </code></pre>
  
  <p>view.php</p>
  
  <pre><code>&lt;?php
  echo $_COOKIE['username'];
  
  
  ?&gt;
  </code></pre>
  
  <p>Error I am getting after unsetting cookie </p>
  
  <p>Notice: Undefined index: username in C:\Users\joe\Documents\Discrete Math\xampp\htdocs\view.php on line 3</p>