function myMain() {
  var nc = Number(prompt("num cards?"));
  var dk = makeDeck(nc);
  
  var hA = dk.deal(5);
  alert(hA[0]); alert(hA[4]);
  
  var hB = dk.deal(7);
  alert(hB[1]); alert(hB[6]);
  
  var ds = dk.size();
  alert(ds);
  alert(dk.getCard(3)); alert(dk.getCard(ds));
  
  return;
}

myMain();

function makeDeck(n) {
  var deck = {
    cards: [],
    shuffle: function() {
      var n1, n2, tmp;
      var nSwaps = 10;
 
      for (var t=0; t<nSwaps; t++) {
        n1 = Math.floor(n*Math.random());
        n2 = Math.floor(n*Math.random());
        tmp = this.cards[n1];
        this.cards[n1] = this.cards[n2];
        this.cards[n2] = tmp;
      }
      return;
    },
    show: function() { alert(this.cards); return; },
    size: function() { return this.cards.length; },
    deal: function(n) {
      var hand = [];
      hand = this.cards.slice(0,n);
      this.cards = this.cards.slice(n);
      return hand;
    },
    getCard: function(n) { return this.cards[n-1]; }
    
  };
  // load initial cards into deck
  for (var i=0; i<n; i++) {
    deck.cards[i] = i;
  }
  return deck;
}