Retrieve Form Key-Values from HttpWebResponse

[Guest]

I have implemented HttpWebRequest and then coded HttpWebResponse which reads
into a stream and then into a string.

By using the resultant string, stream, or Response, how do I get key value
pairs for the response form variables. Is it within
Response.Headers["FormKey1"].ToString()?

or, do I work from the string which was the end result after my
Stream.ReadToEnd()?

Much Appriciated