counter problem :)

gistfile1.js

var counter = function(arg){
  var local;
  function incr(arg2){
    arg2 = arg2 == undefined ? 1 : arg2;
    return !local ? (local = arg2, incr) : (local += arg2, local);
  }
  return incr(arg);
}

var cnt = counter(5);
cnt();
cnt();
console.log(cnt(5));