var mymessage = "Gij zult niet stelen, ( Gebod nr: 3 ) ";
if (document.layers){
document.captureEvents(Event.MOUSEDOWN);
}
function rtclickcheck(keyp){
  if (document.layers && keyp.which != 1) {
    alert(mymessage);
    return false;
  }
  if (document.all && event.button != 1) { 
    alert(mymessage);
    return false;
  }
}
document.onmousedown = rtclickcheck
//-->