There's a nice browser detection script at 
http://www.xs4all.nl/~ppk/js/index.html?version5.html which succesfully 
detects opera.

I agree that opera pretending to be IE is naff - OK it lets you into 
certain sites that wouldn't normally allow opera, but then they don't work 
properly anyway so whats the point?

> You can check the navigator.userAgent property...
> 
> Personally, I think it sucks that you can set a preference like that,
> especially when Opera lacks the DOM support that can be found in IE 5 
> and Netscape 6
> 
> Opera shouldn't event be allowed to claim that they have DOM support, 
when
> they don't even support the crucial document.createElement, appendChild 
etc...
> 
> 
> /Robert Nyman