Parse error: syntax error, unexpected '?' in /volume1/web/greatart/head.sub.php on line 150

Call Stack:
    0.0003     242816   1. {main}() /volume1/web/greatart/bbs/page.php:0
    0.0442     506952   2. include_once('/volume1/web/greatart/bbs/_head.php') /volume1/web/greatart/bbs/page.php:101
    0.0443     507368   3. include_once('/volume1/web/greatart/_head.php') /volume1/web/greatart/bbs/_head.php:3
    0.0443     508192   4. include_once('/volume1/web/greatart/head.php') /volume1/web/greatart/_head.php:4