Closing Standalone Viewers

I very often have two standalone viewer opens to compare two images. It would be very handy to be able to close both viewers with a single command, but I cannot for the life of me work out how to do it.

I tried CLOSEALL, but that does not work.

Dim v
For Each v in DOpus.Viewers
	v.Command("close")
Next

Many thanks, Jon, works a treat.

What would go in a button in the Advanced section to close all standalone viewers? Thanks so much.

I figured it out - open scripting in Advanced. Thanks.