title: How to save a unique file from web browser to the local disk?
body: <p>We have a Web login feature. We will offer Free calls to a large campaign.</p>
  
  <p>Scenarios:</p>
  
  <ul>
  <li>Because of free calls, we will offer a unique file to be downloaded and stored</li>
  <li>After a week or month we will call them and offer them our desktop application to scan and see how trusted, the user is</li>
  <li>If we dont find the same file again, we will never start business and more our own statistics </li>
  <li>Based on that report we want to do some follow ups campaign</li>
  <li>We can do this with cookies but we want user experience and trust analysis</li>
  </ul>
  
  <p>Example: 
  if you play a music in youtube.com, without notice your file is actually in /tmp/Flash....flv with lot of data on it.  </p>
  
  <p>Question:
  How can i do the similar using Flex/Flash from the web browser ? Please kindly advise to any link or existing resource..</p>
  
  <p>Thanks in advance.</p>