title: Delete Saved Proxy Credentials in Firefox
body: <p>I have my proxy credentials saved in a Firefox Portable that I want to share with my friend  but I don't want him to sue my credentials. I've looked around for hours but can't find any way to clear the proxy credentials.</p>
  
  <p>I just want the authentication box to pop up and be empty.</p>
  
  <p>Can anybody point me in the right direction?</p>
  
  <p>Steve</p>