Thanks Wolfgang. I am experimenting with your code and there has arisen a problem. The book I am typesetting has some pages before the text on page-1 starts (cover and so on). Therefore the code
\def\mypageref[#1]{\setpagestate[hvdm][#1]\color[red]{page=\pagenumber\ and pageref=\pagestaterealpage{hvdm}{#1}}}
produces "page=29 and pageref=31". Not as intended. Do I change the macro \pagestaterealpage into what macro? I tried \pagestatepage, but that wasn't the right idea.
Now what further to change?
Hans van der Meer
\definepagestate[hans]
\starttext
One\setpagestate[hans][one]
\page[+2]
Two\setpagestate[hans][two]
Three\setpagestate[hans][three]
\blank
\ifnum0\pagestaterealpage{hans}{two}=0\pagestaterealpage{hans}{one}
The references are on the same page.
\else
The references are on different pages.
\fi
\blank
\ifnum0\pagestaterealpage{hans}{two}=0\pagestaterealpage{hans}{three}
The references are on the same page.
\else
The references are on different pages.
\fi
\stoptext