Install ./install_amp failed on openSUSE

i install freePBX 2.8.1 on openSUSE 11.1,
but when run ./install_amp , there are ERROR in this hyperterminal :

ocki:/usr/src/asterisk/freepbx-2.8.1 # ./install_amp install
Checking for PEAR DB…OK
Checking for PEAR Console::Getopt…OK
Checking user…OK
Checking if Asterisk is running…running with PID: 22911…OK
Checking for /etc/amportal.conf…OK
Reading /etc/amportal.conf…OK
Checking for /etc/asterisk/asterisk.conf…OK
Reading /etc/asterisk/asterisk.conf…OK
Using asterisk as PBX Engine
Checking for Asterisk version…1.4.40
Checking for selinux…sh: getenforce: command not found
OK
Connecting to database…OK
Checking current version of AMP…2.2.0beta3
Installing new FreePBX files…OK (668 files copied, 0 skipped)
PHP Fatal error: Call to undefined function _() in /usr/src/asterisk/freepbx-2.8.1/install_amp on line 1047

Help me please???