Show / hide base on input file value
<p>I have got an input file </p>

<pre><code> &lt;input type="file" name="image" id="file"&gt;
</code></pre>

<p>and a button that save this file</p>

<pre><code> &lt;input type="submit" value="Upload / Edit picture" name="upload_picture" id="upload_picture" class="btn" /&gt;
</code></pre>

<p>I need a JavaScript that will hide button if file was not choosen = 0, else show button if file choosen.</p>
