Imagemaps and layers : request for clarification

Dear Colleagues --

The page

	http://royal-holloway.org.uk/js$opera_demo.html

uses layer clipping to selectively reveal a single orange
diamond over an inferior layer with blue diamonds.  The
page behaves as expected in NS 4.79, NS 7.1 & IE 6, but
does not do so in Opera 7.23.  The first three browsers
allow imagemap clicks and onmouseovers on the non-masked
portion of the inferior layer, whilst Opera allows these
only on the small revealed region of the superior layer.

The problem can be worked around by adding a third (transparent)
layer, the sole function of which is to handle the imagemap
activity, and this can be seen at

	http://royal-holloway.org.uk/

but I would like to know whether Opera or the other three
browsers are behaving in accordance with CSS semantics when
processing

	http://royal-holloway.org.uk/js$opera_demo.html

Your comments and advice would be much appreciated.

Philip Taylor
Webmaster, Royal Holloway

P.S. Apologies in advance if my browser detection code fails to
identify your browser; please let me know if this occurs and
I will endeavour to update the browser-identification regexps
to accommodate your browser.

Received on Monday, 1 March 2004 17:29:01 UTC