オブジェクトの表示

とりあえず：

Object.prototype.toString = function() {

  var s = "{";

  for (var p in this) {

    var v = this[p];

    if (v !== undefined) {

      s += p + "=" + v + ", ";

    }

  }

  s = s.replace(/, $/, "");

  return s + "}";

};