title: using document.cookie to delete cookies not working on firefox
body: <p>below is a simple logout script which is triggered by clicking the "LOGOUT" anchor in the navigation bar in my website.
  the code works fine in chrome but doesn't do a thing in firefox.</p>
  
  <pre><code>            $('a#UserLogout').on('click', function(e){
                  e.preventDefault;
                  document.cookie = '_session_login=""; expires="Thu, 01-Jan-70 00:00:01 GMT";';
                  location.reload();
              });
  </code></pre>
  
  <p>PS. I have another cookie for language preference and it is working code below:</p>
  
  <pre><code>function setCookie(cname,cvalue,exdays)
  {
      var d = new Date();
      d.setTime(d.getTime()+(exdays*24*60*60));
      var expires = "expires="+d.toGMTString();
      document.cookie = cname + "=" + cvalue + "; " + expires;
      location.reload();
  }
  </code></pre>
  
  <p>and i tried using <code>-365</code> in the exdays but didn't work as well</p>