Fatal error: PHP error in file /home/nexaveisolation/forum.nexave.de/lib/page/IrcChatPage.class.php (38): Function ereg_replace() is deprecated

Information:

error message: PHP error in file /home/nexaveisolation/forum.nexave.de/lib/page/IrcChatPage.class.php (38): Function ereg_replace() is deprecated
error code: 0
file: /home/nexaveisolation/forum.nexave.de/wcf/lib/system/WCF.class.php (255)
php version: 5.3.18
wcf version: 1.0.11 pl 4 (Horizon)
date: Sat, 25 May 2013 22:20:35 +0000
request: /index.php?page=IrcChat
referer:

Stacktrace:

#0 [internal function]: WCF::handleError(8192, 'Function ereg_r...', '/home/nexaveiso...', 38, Array)
#1 /home/nexaveisolation/forum.nexave.de/lib/page/IrcChatPage.class.php(38): ereg_replace()
#2 /home/nexaveisolation/forum.nexave.de/wcf/lib/page/AbstractPage.class.php(36): IrcChatPage->show()
#3 /home/nexaveisolation/forum.nexave.de/wcf/lib/util/RequestHandler.class.php(63): AbstractPage->__construct()
#4 /home/nexaveisolation/forum.nexave.de/wcf/lib/util/RequestHandler.class.php(91): RequestHandler->__construct('IrcChat', Array, 'page')
#5 /home/nexaveisolation/forum.nexave.de/index.php(8): RequestHandler::handle(Array)
#6 {main}