+sub precheck_callback {
+ my $cgi = shift;
+ my $o = FS::access_user->new({username => $cgi->param('username')});
+ if( $o->is_system_user and !$cgi->param('usernum') ) {
+ $cgi->param('username','');
+ return "username '".$o->username."' reserved for system account."
+ }
+ return '';
+}