Is it possible to intercept an HTML form post and do some processing before sending it to it's final destination?
<p>I'm trying to extend the functionality of an ASP.net application that I'm working with. For its logon page, it uses an html form to post to a dll to handle it's login logic.</p>

<p>I'm wondering if there is any way to redirect that html POST to my C# code so that I can do some processing and then (and this is the part that I haven't figured out yet) POST it to the dll so that the regular logon logic can continue.</p>

<p>I can make changes to the logon page, but the final step must be to do an HTML POST to the dll. I can't change that.</p>
