if(navigator.appVersion.charAt(0) >= "3") {
   var img = new Array();
     img[0] = new Image();  img[0].src = "../bg/off_back.gif";
     img[1] = new Image();  img[1].src = "../bg/on_back.gif";
     img[2] = new Image();  img[2].src = "../bg/off_nav.gif";
     img[3] = new Image();  img[3].src = "../bg/over_nav.gif";
     img[4] = new Image();  img[4].src = "../bg/on_nav.gif";
    }

  function _inout(nam,num) {
    if(navigator.appVersion.charAt(0) >= "3") {
      document.images[nam].src = img[num].src;
     }
   }

  function _back1() {
    if(navigator.appVersion.charAt(0) >= "3") {
      parent.mimo.history.back();
     }
   }
  function _back2() {
    if(navigator.appVersion.charAt(0) < "3") {
      url = parent.haizuka.document.referrer;
      if (url == '') {
        url = 'http://www.ny.airnet.ne.jp/haizuka/2000/';
       }
      parent.haizuka.location = url;
     }
   }