fix dereference

booking.helper.inc

@@ -1325,7 +1325,8 @@ function _booking_get_person_fields() {
 	$result = $query->fetchAll();
 	
 	foreach ($result as $column) {
-		$list_of_columns->$column['Field'] = $column['Field']; 
+		$field = $column->Field;
+		$list_of_columns->$field = $field; 
 	}
 	
 	watchdog('booking_debug', "<pre>Database columns for booking_person\n@info</pre>", array('@info' => print_r( $list_of_columns, true)));