Its a complete waste of time. You could look at the source code, find the url to an image, type it in the address bar and save the result.
This seems to work:
<img ... oncontextmenu="return false;">
..until you try it in more than one particular browser.
The question was only about one particular browser, Firefox.
I'm a fan of the transparent GIF overlay. That way they think they've saved the image, but noooo. . .
What ever kind of protection you try to involve in your page with no right click is pointless, you will only fool a newbie... source is always reachable you can also copy screen or acces cache ...
If you really want to protect your images, put a copyright on them, that about all you can do except not puting them at all ...
Apologies, jollyfmcats, I reaally should try to keep up. Looks like oncontext menu is supported by Mozilla. ( [lab.artlung.com...] ).
Not by Opera, it seems, but it still means very reasonable coverage.
I had a feeling the SP2 disabled this feature, but I can't test that.
It still works on XP Pro, SP 2.
Firefox has an option ignore JS code that disables the context menu, so you can't rely on an oncontextmenu="return false;".
kaled is right, it's a waste of time. I don't even have a right mouse button and can quite easily copy anything protected that way ;)
the right click js is such an old trick,just edit>select all>copy
or easier view source
or edit with front page(IE)
or print screan copy paste in Photo shop
There is a phenominaly complex way ...involving only delivering images if the user has .js accepted and banning all bots from your image files and crypting the calls to the .js files and crypting the paths to your image files and etc etc etc and hacking the user computer to prevent screen capture in all browsers etc etc..and htaccess restrictions ..
Been there done that ..stopped doing it ( most browsers thought my site was installing malware ;) ..locked up visitors machines and required reboot of their system so they could get back their clipboard facility ..;)
very very bad for PR ..( public relations ..not page rank )
Use watermarks ..life is complicated enough as it is ..