function getCookie(name) {
  var arg = name + "=";
  var alen = arg.length;
  var clen = document.cookie.length;
  var i = 0;
  while (i < clen) {
    var j = i + alen;
    if (document.cookie.substring(i, j) == arg)
      return getCookieVal (j);
    i = document.cookie.indexOf(" ", i) + 1;
    if (i == 0) break;
  }
  return null;
}
function getCookieVal(offset) {
  var endstr = document.cookie.indexOf (";", offset);
  if (endstr == -1)
    endstr = document.cookie.length;
  return unescape(document.cookie.substring(offset, endstr));
}
function setCookie(name, value) {
  var argv = setCookie.arguments;
  var argc = setCookie.arguments.length;
 
  var expires = (argc > 2) ? argv[2] : null;
  var path = (argc > 3) ? argv[3] : null;
  var domain = (argc > 4) ? argv[4] : null;
  var secure = (argc > 5) ? argv[5] : false;
  document.cookie = name + "=" + escape (value) + 
     ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + 
     ((path == null) ? "" : ("; path=" + path)) +  
     ((domain == null) ? "" : ("; domain=" + domain)) +    
     ((secure == true) ? "; secure" : "");
  
}
function delCookie(name) {
  exp = new Date();
  exp.setTime(exp.getTime() - (24*60*60*1000));
  var cval = getCookie(name);
  cval = (cval == null) ? "" : cval;
  document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}