acid+php problem

["Baterdene.D" <dbaterdene () micom mng net>]

Hi list
i have problem with displaying alerts on acid.

It can not display the alert with
details,
it always prompted with following line..
    Fatal error: Call to undefined function: preg_replace() in
/usr/local/www/acid/acid_signature.inc on line 194

What's the problem? Any suggestions?

Baterdene.D
Engineer of Micom Company
Ulaanbaatar
Mongolia