expireDate = new Date();
expireDate.setMonth(expireDate.getMonth() + 60);

graphic = cookieVal("imageName");
if (graphic == "0") {
  graphic = "icons/default.gif"
  document.cookie = "imageName=" + graphic + "; expires=" + expireDate.toGMTString();
}
else {
  document.cookie = "imageName=" + graphic + "; expires=" + expireDate.toGMTString();
}

function cookieVal(cookieName) {
  thisCookie = document.cookie.split("; ");
  for (i=0; i<thisCookie.length; i++) {
    if (cookieName == thisCookie[i].split("=")[0]) {
      return thisCookie[i].split("=")[1];
    }
  }
  return 0
}