note 58161 added to function.mb-convert-encoding

I've downloaded and install PHP 5.0.5 + Apache 2.0.55 and can't get rid of this function - it returns: --Call to undefined function mb_convert_encoding() -- maybe someone have any solution? ---- Manual Page -- http://www.php.net/manual/en/function.mb-convert-encoding.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+58161 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+58161&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+58161&report=yes Search -- http://master.php.net/manage/user-notes.php