Disable Right Click on images

Recently a client asked me to disable right clicks on their images, as they are copyrighted.
A quick search revealed one solution that I'm outlining below.

Place the following in a javascript script:


var disableclickmessage = 'Copyright company.\nAll rights reserved.';
function disablerightclick(event) {
if (document.all) {
if (event.button==2||event.button==3) {
if (event.srcElement.tagName=="IMG"){
alert(disableclickmessage);
}
}
} else if (document.layers) {
if (event.which == 3) {
alert(disableclickmessage);
}
} else if (document.getElementById){
if (event.which==3&&event.target.tagName=="IMG"){
alert(disableclickmessage)
}
}
return false;
}



Usage:

img style="width: 93px; height: 24px;" src="test.jpg" onmousedown="disablerightclick(event)"