var onImgs = new Array();
onImgs['mainnav1'] = new Image();
onImgs['mainnav2'] = new Image();
onImgs['mainnav3'] = new Image();
onImgs['mainnav4'] = new Image();
onImgs['mainnav5'] = new Image();
onImgs['mainnav6'] = new Image();

onImgs['subnav1'] = new Image();
onImgs['subnav2'] = new Image();
onImgs['subnav3'] = new Image();
onImgs['subnav4'] = new Image();
onImgs['subnav5'] = new Image();
onImgs['subnav6'] = new Image();

onImgs['mainnav1'].src = '/img/en/menu_main_01_on.gif';
onImgs['mainnav2'].src = '/img/en/menu_main_02_on.gif';
onImgs['mainnav3'].src = '/img/en/menu_main_03_on.gif';
onImgs['mainnav4'].src = '/img/en/menu_main_04_on.gif';
onImgs['mainnav5'].src = '/img/en/menu_main_05_on.gif';
onImgs['mainnav6'].src = '/img/en/menu_main_06_on.gif';

onImgs['subnav1'].src = '/img/en/menu_sub_01_on.gif';
onImgs['subnav2'].src = '/img/en/menu_sub_02_on.gif';
onImgs['subnav3'].src = '/img/en/menu_sub_03_on.gif';
onImgs['subnav4'].src = '/img/en/menu_sub_04_on.gif';
onImgs['subnav5'].src = '/img/en/menu_sub_05_on.gif';
onImgs['subnav6'].src = '/img/en/menu_sub_06_on.gif';

function imgOn(imgName){
  if (document.images){
    document.images[imgName].style.cursor = 'pointer';
    document.images[imgName].src = onImgs[imgName].src;
  }
}

var offImgs = new Array();
offImgs['mainnav1'] = new Image();
offImgs['mainnav2'] = new Image();
offImgs['mainnav3'] = new Image();
offImgs['mainnav4'] = new Image();
offImgs['mainnav5'] = new Image();
offImgs['mainnav6'] = new Image();

offImgs['subnav1'] = new Image();
offImgs['subnav2'] = new Image();
offImgs['subnav3'] = new Image();
offImgs['subnav4'] = new Image();
offImgs['subnav5'] = new Image();
offImgs['subnav6'] = new Image();

offImgs['mainnav1'].src = '/img/en/menu_main_01.gif';
offImgs['mainnav2'].src = '/img/en/menu_main_02.gif';
offImgs['mainnav3'].src = '/img/en/menu_main_03.gif';
offImgs['mainnav4'].src = '/img/en/menu_main_04.gif';
offImgs['mainnav5'].src = '/img/en/menu_main_05.gif';
offImgs['mainnav6'].src = '/img/en/menu_main_06.gif';

offImgs['subnav1'].src = '/img/en/menu_sub_01.gif';
offImgs['subnav2'].src = '/img/en/menu_sub_02.gif';
offImgs['subnav3'].src = '/img/en/menu_sub_03.gif';
offImgs['subnav4'].src = '/img/en/menu_sub_04.gif';
offImgs['subnav5'].src = '/img/en/menu_sub_05.gif';
offImgs['subnav6'].src = '/img/en/menu_sub_06.gif';

function imgOff(imgName){
  if (document.images){
    document.images[imgName].style.cursor = 'pointer';
    document.images[imgName].src = offImgs[imgName].src;
  }
}