I am trying the simplest possible example of knockout.js but it doesn't work (first and last names stay empty). I put my script tags after html tags that use binding and call ko.applyBindings after page loads. Alert works so the function fires. Any help?

```
<p>First name: <strong data-bind="text: firstName"></strong></p>
<p>Last name: <strong data-bind="text: lastName"></strong></p>

<script type="text/javascript' src='js/knockout-3.4.0.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script type="text/javascript">
function AppViewModel() {
    alert("b");
    this.firstName = "Bert";
    this.lastName = "Bertington";
}

$(window).load(function() {
    ko.applyBindings(new AppViewModel());
});
</script>

```

EDIT
This problem is solved, but I have another one. What to do if I wanted to add first and last name simultaneously after clicking the button (not when inputs lose focus)?

```
<p>First name: <input data-bind="value: firstName" /></p>
<p>Last name: <input data-bind="value: lastName" /></p>

<a class="btn btn-primary btn-lg"  role="button"  >Add</a>

<p>First name: <strong data-bind="text: firstName"></strong></p>
<p>Last name: <strong data-bind="text: lastName"></strong></p>

<script type="text/javascript" src="js/knockout-3.4.0.js"></script>
<script type="text/javascript">

function AppViewModel() {
  this.firstName = ko.observable();
  this.lastName = ko.observable();
}

ko.applyBindings(new AppViewModel());

</script>

```