--- lib/A3C/Model/StrixInstanceSelection.pm	2008/06/16 22:17:06	185
+++ lib/A3C/Model/StrixInstanceSelection.pm	2008/06/16 22:56:14	186
@@ -12,6 +12,7 @@
 		label is _('Instance identifier'),
 		is mandatory,
 		type is 'text',
+		is ajax_validates,
 		refers_to A3C::Model::StrixInstance by 'instance';
 
 	column by_user =>
@@ -33,8 +34,15 @@
 	my $strix = A3C::Model::StrixInstanceSelection->new;
 	$strix->load_by_cols( instance => $instance );
 
-	return ( 0, _('Instance %1 is allready selected', $instance) ) if $strix->id;
-	return 1;
+	if ( $strix->id ) {
+		return ( 0, _('Instance %1 allready selected', $instance) );
+	} else {
+		eval {
+			Strix->dbh( $instance );
+		};
+		return 1 unless $@;
+		return ( 0, $@ );
+	}
 }
 
 sub current_user_can {