title: How to compare selected files with js
body: <p>I'm using <a href="https://github.com/blueimp/jQuery-File-Upload" rel="nofollow">https://github.com/blueimp/jQuery-File-Upload</a> to upload files. But basicly it uses native javascript <em>File</em> interface. And i need to check if user didn't upload same file twice. Problem is that <em>File</em> interface does'n allow to access file path.</p>
  
  <p>So how do I compare files with minimum system load?
  Thanks.</p>