Problem using InteractJS

I have a problem trying to use the InteractJS library as a library.

At this moment my code , as you can see, is invoking the necessary files for the correct execution of the example: / p>

<link href="css/drag-drop.css" rel="stylesheet">

and

<script src="js/drag-drop.js"></script>

However, the behavior does not occur.

The HTML code is as exemplified on the page:

<div id="no-drop" class="draggable drag-drop"> #no-drop </div>

    <div id="yes-drop" class="draggable drag-drop"> #yes-drop </div>

    <div id="outer-dropzone" class="dropzone">
        #outer-dropzone
    <div id="inner-dropzone" class="dropzone">#inner-dropzone</div>

</div>

I can not understand what I'm doing wrong.