function getCookieVal (offset) {
   var endstr = document.cookie.indexOf (";", offset);
   if (endstr == -1)
      endstr = document.cookie.length;
   return unescape(document.cookie.substring(offset, endstr));
}

function getCookie (strName) {
   var arg  = strName + "=";
   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;
}