if (window.Event) document.captureEvents(Event.MOUSEUP); 
if (document.layers) document.captureEvents(Event.MOUSEDOWN); 
function nocontextmenu() { event.cancelBubble = true ; event.returnValue = false; return false; }
function norightclick(e) { if (window.Event) { if (e.which == 2 || e.which == 3) return false;  } else if (event.button == 2 || event.button == 3) { event.cancelBubble = true; event.returnValue = false; return false; } } 
document.oncontextmenu = nocontextmenu; document.onmousedown = norightclick; document.onmouseup = norightclick;