g_return_val_if_fail(CAPTIVE_FILE_IS_OBJECT(captive_file_object),GNOME_VFS_ERROR_BAD_PARAMETERS);
if (captive_file_object->vfs!=NULL) {
g_return_val_if_fail(CAPTIVE_FILE_IS_OBJECT(captive_file_object),GNOME_VFS_ERROR_BAD_PARAMETERS);
if (captive_file_object->vfs!=NULL) {