How do you programmatically fill in a form and 'POST' a web page?

Question

Using C# and ASP.NET I want to programmatically fill in some values (4 text boxes) on a web page (form) and then 'POST' those values. How do I do this?

Edit: Clarification: There is a service (www.stopforumspam.com) where you can submit ip, username and email address on their 'add' page. I want to be able to create a link/button on my site's page that will fill in those values and submit the info without having to copy/paste them across and click the submit button.

Further clarification: How do automated spam bots fill out forms and click the submit button if they were written in C#?

Answer 1

The code will look something like this:

WebRequest req = WebRequest.Create("http://mysite/myform.aspx"); string postData = "item1=11111&item2=22222&Item3=33333";  byte[] send = Encoding.Default.GetBytes(postData); req.Method = "POST"; req.ContentType = "application/x-www-form-urlencoded"; req.ContentLength = send.Length;  Stream sout = req.GetRequestStream(); sout.Write(send, 0, send.Length); sout.Flush(); sout.Close();  WebResponse res = req.GetResponse(); StreamReader sr = new StreamReader(res.GetResponseStream()); string returnvalue = sr.ReadToEnd();