Event.observe(window, 'load', function() {
    images = document.getElementsByTagName('img');
    for (var i = 0; i < images.length; i++) {
        images[i].oncontextmenu = mischandler;
        images[i].onmousedown = mousehandler;
        images[i].onmouseup = mousehandler;
    }
});

var isNS = (navigator.appName == "Netscape") ? 1 : 0;
if(navigator.appName == "Netscape")
    document.captureEvents(Event.MOUSEDOWN||Event.MOUSEUP);

function mischandler(){
    return false;
}
    
function mousehandler(e){
    var myevent = (isNS) ? e : event;
    var eventbutton = (isNS) ? myevent.which : myevent.button;
    if((eventbutton==2)||(eventbutton==3)) return false;
}