httpwebrequest question

 I have built a "middlepage" between two web sites. I take values passed from one web page, look up data, and pass this data to a second page.
This all works good. However, sometimes I want to pass the data and actually redirect the user to the second page. I can use respond.redirect and pass the values using paramters.
However, I want to use a POST to pass the data AND redirect the user to that page.
That is why I attempted to use HttpWebRequest. I am able to pass the values using the POST method, but I cannot figure out how to transfer control to the second page.
My code is below - any help is appreciated...















"redirectpath" is the URL of my second page..."post_string" is the parameter key ...