Object.prototype.toString = function() {
  var r = "{", first = true
  for (var p in this) {
    if (!this.hasOwnProperty(p)) continue
    if (first) first = false
    else r += ", "
    r += p + ": " + this[p]
  }
  return r + "}"
}
Object.prototype.search = function(str, action) {
  for (var p in this)
    if (this.hasOwnProperty(p) && this[p].toLowerCase().indexOf(str.toLowerCase()) >= 0)  
      action(this, p)
}

Stack = function(cards) { this.cards = cards }
Stack.prototype.search = function(str, action) {
  for (var i = 0; i < this.cards.length; i++)
    this.cards[i].search(str, action)
}

s = new Stack([
  {
    name: 'alex',
    car: 'honda civic'
  },
  {
    name: 'takashi',
    car: 'toyota yaris'
  },
  {
    name: 'yoshiki',
    car: 'toyota prius'
  }
])

s.search("toyota", function(obj, prop) { alert(obj + "." + prop + "=" + obj[prop]) })