if(navigator.appVersion.charAt(0) >= "3"){
  img_top = new Array();
  img_top[1] = new Image; img_top[1].src = "pic/ctgry_menu01_ovr.gif";
  img_top[2] = new Image; img_top[2].src = "pic/ctgry_menu01_off.gif";

  img_top[4] = new Image; img_top[4].src = "pic/ctgry_menu02_ovr.gif";
  img_top[5] = new Image; img_top[5].src = "pic/ctgry_menu02_off.gif";

  img_top[7] = new Image; img_top[7].src = "pic/top_button_gv_ovr.gif";
  img_top[8] = new Image; img_top[8].src = "pic/top_button_gv_off.gif";

  img_top[10] = new Image; img_top[10].src = "pic/top_button_cz_ovr.gif";
  img_top[11] = new Image; img_top[11].src = "pic/top_button_cz_off.gif";

  img_top[13] = new Image; img_top[13].src = "pic/top_button_es_ovr.gif";
  img_top[14] = new Image; img_top[14].src = "pic/top_button_es_off.gif";

}

function chg_img(DocName,ImgNum){
  if(navigator.appVersion.charAt(0) >= "3"){
    document.images[DocName].src=img_top[ImgNum].src;
  }
}