Webmaster Forum / HTML, CSS, Scripts / CSS / November 2005

Can someone point me to a good explanation of how to use opacity?
From CSS 3 http://www.w3.org/TR/2003/CR-css3-color-20030514/#opacity 
which I read to mean just set a decimal value between 0 and 1

I tried using opacity: 0.50;  and it appeared to work as expected in
Safari and Firefox, but not in Opera.  Does it actually work in any
version of IE?  Does it degrade harmlessly like in Opera?

I also noticed the use of  filter: alpha(opacity=50);  apparently for
Internet Explorer only, and added that in an attempt to provide
something for IE to use also.

However the CSS validator says property opacity doesn't exist about the
first version, and says parse error opacity=50 about the second.  I
guess that is a reasonable error message about the second if it is an IE
only variation.  But I don't understand what CSS syntax I should use
instead of opacity: 0.50; if I have that wrong.

I tried both of these in http://www.sheltersrus.com.au/horse.html with
http://www.ericlindsay.com/sheltersrus.css controlling the opacity of
the text of the pseudo logo that should be in the top left hand corner
of the page (I am just using that photo for test purposes).  As I said,
works in Firefox and Safari.  If the "logo" falls down the page in IE
that would be nice to know also (I have dark suspicions of things
breaking).