I'm trying to store the value of a input field into a variable. But it doesn't seem to work. What am I doing wrong? I know there are other ways and I will probably change it later anyway. But right now I'm just really curious why this doesn't work:

<http://codepen.io/ttimon/pen/PGYapa>

```
<div id="searchInput" class="form-group">
  <input type="text" class="form-control" id="usr" placeholder="Type your search term here...">
  </div>
  <button id="search" class="button" onclick="searchWiki();">Search</button>

</div>

$( document ).ready(function() {
    function searchWiki() {
      var search = document.getElementbyId("usr").value;
      alert(search);
} 

});

```

thanks for your help