[Vlasenko Fedor]

<script>
  function person() {
    this.sex = "";
    this.name = "";
  }
  var persona = new person();
  var reg = /^.*?\s(.*)\(/
  alert("Function name - " + reg.exec(persona.constructor.toString())[1]);
  alert("Function name - " + persona.constructor.name);
</script>

<script>
  function person() {
    this.sex = "";
    this.name = function () {
      return this.constructor.name;
    }
  }
  var persona = new person();;
  alert("Function name - " + persona.name());
</script>