title: XMLHttpRequest, basic authentication and expiring password
body: <p>I use XMLHttpRequest and basic-auth to access application interface. Password is temorary and is generated by other request, so it expires after some time.</p>
  
  <p>But browser (Firefox least) keep using old one, failing and showing login popup. If i suppress popup by returning 403 for requests with X-Requested-By and wrong password, mozilla never tries to use new password (firebug shows new password in request, server receives old).</p>
  
  <p>Problem can be evaded by adding random 'salt' to username (and stripping it at server side), but is there better way to force XMLHttpRequest use provided password instead of cached?</p>