var bannerCnt;
var bannerIdx = 0;

$(document).ready(function() {
  bannerCnt = $(".imgbanner").length;
  $("#header").css("background-image", "none");
  
  bannerIdx = parseInt($.cookie("bannerIdx")) + 1;
  if ($.cookie("bannerIdx") == 'NaN') bannerIdx = 0;
  if (bannerIdx >= bannerCnt) bannerIdx = 0;
  $.cookie("bannerIdx", bannerIdx);
  if (isNaN(bannerIdx)) bannerIdx = 0;
  
  $("#bmg" + bannerIdx).show();
  if (bannerCnt > 1) setInterval("changeBanner()", 10000);
});

function changeBanner() {
  $("#bmg" + bannerIdx).fadeOut(2000);
  bannerIdx++;
  if (bannerIdx == bannerCnt) bannerIdx = 0;
  $.cookie("bannerIdx", bannerIdx);
  $("#bmg" + bannerIdx).fadeIn(2000);  
}