500 Server Error

A misconfiguration on the server caused a hiccup. Check the server logs, fix the problem, then try again.
URL: http://lita.giftbag.com.tw/500.php

Notice: Use of undefined constant DOCUMENT_ROOT - assumed 'DOCUMENT_ROOT' in /home/giftbagc/public_html/litabedroom.com/500.php on line 12

Notice: Use of undefined constant REQUEST_URI - assumed 'REQUEST_URI' in /home/giftbagc/public_html/litabedroom.com/500.php on line 12

Warning: escapeshellarg() has been disabled for security reasons in /home/giftbagc/public_html/litabedroom.com/500.php on line 12

Warning: shell_exec() has been disabled for security reasons in /home/giftbagc/public_html/litabedroom.com/500.php on line 13