text: "use strict";
  
  var info = document.getElementById("info");
  var persons = document.querySelectorAll(".person");
  
  var i;
  for (i=0; i<persons.length; i++) {
    persons[i].addEventListener("click", function(event) {
      event.preventDefault();
      var person = event.target;
      var href = person.getAttribute("href");
      var content = person.dataset.content;
      window.history.pushState(content, null, href);
      info.innerHTML = content;
    }, false);
  }
  
  window.addEventListener("popstate",function(event) {
    if (event.state === null) {
      info.innerHTML = "Entry Page";
    } else {
      info.innerHTML = event.state;
    }
  }, false);
  