this would fit more in the Serlvet Forum.
The HTML Page (no matter with wath technology you generate it, be it JSP, PHP, ...) "lives" in the users browser.
To grab user input you need a form and input elements in the HTML page. When the submit button is clicked, then the browser sends the form data to the URL specified in the action attribute of the form.
You need to have something (a Servlet/JSP) "listening" on that URL. The
servlet can access the form data through the HttpServletRequest Object (getParameter()/getParameters() methods) and insert the values in a DB, print them... whatever you want. Then the Servlet redirects or forwards to a result page. Voila....
hope this helped...
pascal