JS get a cookie

gistfile1.js

      getCookie : function(cookieID) {
        var dc = document.cookie, prefix = cookieID + "=", begin = dc.indexOf("; " + prefix);
        if (begin == -1) {
          begin = dc.indexOf(prefix);
          if (begin != 0)
            return null;
        }
        else
          begin += 2;
        var end = document.cookie.indexOf(";", begin);
        if (end == -1)
          end = dc.length;
        return unescape(dc.substring(begin + prefix.length, end));
      }