All I needed was the "host" portion of the URL in my left frame. Fortunately,
the location object gives you this reference (e.g  top.leftframe.location.host).
It would be nice though, to reference any element in any frame being displayed.
I think MS took the "sandbox" approach to frames, giving each one it's own
seperate namespace and environment.

I did experiment with defining a global variable in the uppermost document (the
one containing the framesets) but couldn't access it from the frames underneath
that. It would have been nice to define a set of common functions in there too,
globally accessible but alas, this was not to be...

Thanks to all who responded to this.

Problem solved (until the next time...)

Mark W.