if(navigator.appVersion.charAt(0) >= "3"){
  img = new Array();
  img[0] = new Image; img[0].src = "/images/navi/top.gif";
  img[1] = new Image; img[1].src = "/images/navi/top2.gif";
  img[2] = new Image; img[2].src = "/images/navi/hp.gif";
  img[3] = new Image; img[3].src = "/images/navi/hp2.gif";
  img[4] = new Image; img[4].src = "/images/navi/flow.gif";
  img[5] = new Image; img[5].src = "/images/navi/flow2.gif";
  img[6] = new Image; img[6].src = "/images/navi/websystem.gif";
  img[7] = new Image; img[7].src = "/images/navi/websystem2.gif"; 
  img[8] = new Image; img[8].src = "/images/navi/works.gif";
  img[9] = new Image; img[9].src = "/images/navi/works2.gif";
  img[10] = new Image; img[10].src = "/images/navi/server.gif";
  img[11] = new Image; img[11].src = "/images/navi/server2.gif";
  img[12] = new Image; img[12].src = "/images/navi/contact.gif";
  img[13] = new Image; img[13].src = "/images/navi/contact2.gif";
  img[14] = new Image; img[14].src = "/images/navi/company.gif";
  img[15] = new Image; img[15].src = "/images/navi/company2.gif";
}
 function chg_img(imgname,a){  
   if(navigator.appVersion.charAt(0) >= "3"){
     document.images[imgname].src=img[a].src;
  }
}