THIS SCRIPT IS
NOT FOOL-PROOF !!
(Excerpts from Martin Webb's well-worded explanation)
Bearing this in mind, the following script should stop right clicks (and left button held down, followed by a right click) in both Netscape Navigator and Microsoft Internet Explorer. It will not stop users who use a Mac - where the mouse only has one button.
If this script doesn't do what you require (i.e. protect your images and or your scripts) then don't use it and don't put your images/scripts on the net. If your livelihood relies on people not copying your images - then add a water mark or "sample" stamp to your images.