var onImgs = new Array();
onImgs['btnmotos'] = new Image();
onImgs['btnpower'] = new Image();
onImgs['btnmarine'] = new Image();
onImgs['btnused'] = new Image();
onImgs['btnservice'] = new Image();

onImgs['btnmotos'].src = 'http://www.excelhondamoto.com/img/en/nav_01_on.gif';
onImgs['btnpower'].src = 'http://www.excelhondamoto.com/img/en/nav_02_on.gif';
onImgs['btnmarine'].src = 'http://www.excelhondamoto.com/img/en/nav_03_on.gif';
onImgs['btnused'].src = 'http://www.excelhondamoto.com/img/en/nav_04_on.gif';
onImgs['btnservice'].src = 'http://www.excelhondamoto.com/img/en/nav_05_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['btnmotos'] = new Image();
offImgs['btnpower'] = new Image();
offImgs['btnmarine'] = new Image();
offImgs['btnused'] = new Image();
offImgs['btnservice'] = new Image();

offImgs['btnmotos'].src = 'http://www.excelhondamoto.com/img/en/nav_01.gif';
offImgs['btnpower'].src = 'http://www.excelhondamoto.com/img/en/nav_02.gif';
offImgs['btnmarine'].src = 'http://www.excelhondamoto.com/img/en/nav_03.gif';
offImgs['btnused'].src = 'http://www.excelhondamoto.com/img/en/nav_04.gif';
offImgs['btnservice'].src = 'http://www.excelhondamoto.com/img/en/nav_05.gif';

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