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(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;
}