[SM-USERS] Addressbook problems

[Mail]

I hope someone can help me   I have been running Squirrelmail for a few months now but still have not been able to sort out a problem   I am running Windows XP, IIS, Mercury Mail, PHP, all latest versions and service packs   My Squirrelmail seems to run ok, I can view e-mails etc from remote locations, but whenever I try and send an e-mail or add an address I get an error message such as:   Fatal error: Call to a member function on a non-object in C:\www\sm\functions\addressbook.php on line 288   I am not an expert in php but cannot see the reason for the error   Line 288 reads:             $res = $this->backends[$bnum]->lookup($alias);   In the context of:     /*      *  Lookup an address by alias. Only possible in      *  local backends.      */     function lookup($alias, $bnum = -1) {              $ret = array();              if ($bnum > -1) {             $res = $this->backends[$bnum]->lookup($alias);             if (is_array($res)) {                return $res;             } else {                $this->error = $backend->error;                return false;             }         }      I am certain its a configuration error on my part but don't know how to fix it   I am not using a database back-end, I only have a few addresses to keep so have tried to use the file address book   Locally I use Outlook Express to access my mail and it sends mail with no problem   Any ideas?