How to close open ways in JOSM

I have created a large lake boundary and wanted to merge wit with the other boundary but I need to close t first. How to do that.

(Ok I have manually found the unclosed way and closed it. But will still need to know how to do it with a shortcut).

Can someone check if this lake ‘Manikdoh’ is OK in terms of relations and etc (outer etc)

https://www.openstreetmap.org/#map=16/19.2589/73.7682

Hello, You’ve actually created two relations for the area.

‘Relation: Manikdoh (7953581)’ with the two outer ways is OK, tags are OK, possible tag to add is reservoir_type=water_storage.

‘Relation: Manikdoh reservoir (7953582)’ has the two outer ways and includes three inner ways which I cannot see on the Bing image, these look to be fiction and if so should be removed. This relation is a duplicate so should be removed entirely with the fictional inner ways. If my assumption of the inner ways is wrong my apologies.

There is also an untagged ‘Node: 5374420498’ which looks to serve no purpose so could be removed.

Regards Bernard

Thanks! Done!