[NTG-context] thumb index: \setlayer on every odd/even page?

Hai, how must I setup layers that get repeated on every even/odd page? Or should I use \doifoddpageelse with \setlayer? Or do you have a different suggestion for thumb index “boxes”? Greetlings, Hraban --- https://www.fiee.net http://wiki.contextgarden.net https://www.dreiviertelhaus.de GPG Key ID 1C9B22FD