Happy-the-monk provided the correct answer here. I'm just going to add a bit of explanation, since your use of terminology may indicate a little bit of confusion.

The code snippet that you cited would not normally be called a script. This is just an HTML page that calls a script. When someone visits your web page, his browser downloads that information and draws the page. When the user clicks on "submit", that information is sent back to your webserver and given to the program entitled "responsetest.cgi". As you have written the program, that program will need to be in the same directory as your web page. If your web server is running some version of Unix, that file must also be set as a "runnable file" (that is, the file permissions should be 755). On any web server, you will have to have the server set up to handle cgi scripts in any directory. If that's not the case and you don't know how to change it, you can usually put your script in the "cgi-bin" directory, and then access it as

<form action="/cgi-bin/responsetest.cgi" method="post">

The script responsetest.cgi will be written in perl (of course) and should use the CGI.pm module to avoid a lot of security problems. As Happy-the-monk showed, you will very easily be able to access the values put into your HTML form from within a CGI.pm-using perl script.