if (window.Event) 
document.captureEvents(Event.MOUSEUP); 
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;