getting custom headers

I have an ajax request to my rails app that uses a header named "X- Requires-Resp"

How can I access this header's value in my controller?

It doesn't work, plus I get a deprecation warning. Any other ideas? I have no idea why this would be so hard...!

I think you just get them CGI-style:

  request.env['HTTP_X_REQUIRES_RESP']

THANK YOU!!!