function click(e) 
{
	if (document.all) 
	{
		if (event.button == 2) 
		{
			copyright_message();
			return false;
		}
	}

	if (document.layers) 
	{
		if (e.which == 3) 
		{
			copyright_message();
			return false;
		}
	}
}

function copyright_message()
{
    var message="Copyrighted material."; 
    alert(message);
}

if (document.layers) 
{
	document.captureEvents(Event.MOUSEDOWN);
}

document.onmousedown=click;