module.exports = function checkNationalCode(code) {
   var L = code.length

   if (L < 8 || parseInt(code, 10) == 0) return false
   code = ('0000' + code).substr(L + 4 - 10)
   if (parseInt(code.substr(3, 6), 10) == 0) return false
   var c = parseInt(code.substr(9, 1), 10)
   var s = 0
   for (var i = 0; i < 9; i++) {
      s += parseInt(code.substr(i, 1), 10) * (10 - i)
   }
   s = s % 11;
   return (s < 2 && c == s) || (s >= 2 && c == (11 - s))
}