title: codeigniter sessions creates two different sessions
body: <p>Codeigniter sessions creating two different session for same website name.</p>
  
  <p><strong>Scenario:</strong></p>
  
  <ol>
  <li>domainname.com</li>
  <li>www.domainname.com</li>
  </ol>
  
  <p>In both cases it is creating two different sessions. But when I type the same url in IE-10 it's creating only single session, but it is not working in firefox &amp; chrome.</p>
  
  <p>My <strong>ci_config</strong> file is as follows:</p>
  
  <pre><code>$config['sess_cookie_name']     = 'ci_session';
  $config['sess_expiration']      = 0;
  $config['sess_expire_on_close'] = FALSE; 
  $config['sess_encrypt_cookie']  = FALSE;
  $config['sess_use_database']    = TRUE;
  $config['sess_table_name']      = 'ci_sessions';
  $config['sess_match_ip']        = FALSE;
  $config['sess_match_useragent'] = TRUE;
  $config['sess_time_to_update']  = 1800; 
  </code></pre>
  
  <p>Can anyone please suggest a way to resolve this?</p>