var str_end, arg, arg_len, c_len, i, j;
    
    function getCookie(var_name)
    {
        if (document.cookie)
        {
            arg     = var_name + "=";
            arg_len = arg.length;
            c_len   = document.cookie.length;
            i       = 0;
            while (i < c_len) 
            {
                   j = i + arg_len;
                   if (document.cookie.substring(i, j) == arg)
                   {
                       str_end = document.cookie.indexOf (";", j);
                       if (str_end == -1) { str_end = c_len; }        
                       return unescape(document.cookie.substring(j, str_end));
                       break;
                   }
                   i = document.cookie.indexOf(" ", i) + 1;
                   if (i == 0) { break; }
           }
        }
        return null;
   }