function mdown(e) {
  if (navigator.appName == "Microsoft Internet Explorer") {
    if (event.button == 2) {
	alert("http://www.man-navi.com/");
      return(false);
    }
  } else if (navigator.appName == "Netscape") {
    if (e.which == 3) {
      alert("http://www.kk.iij4u.or.jp/~shy/");
      return(false);
    }
  }
}
if (document.all) {
  document.onmousedown = mdown;
}
if (document.layers) {
  window.onmousedown = mdown;
  window.captureEvents(Event.MOUSEDOWN);
}

if(document.layers)document.captureEvents(Event.MOUSEDOWN);
document.onmousedown=mdown;