Please Help me

Even with your bookish knowledge, you should be able to make out [I don't blame you for confusing though] that servlets and EJBs are intended for a different purposes. Servlets are intended to handle requests for different protocols, the most common being HTTP for web applications. EJBs are, on the other hand, business components, which encapsulate business logic.

When you are talking about the example of a login page, after you submit, the browser generates a HTTP request, which can be handled by a servlet (in J2EE). EJBs are not designed to handle these. They come into picture when some business processing needs to be done. In the login case, you may have an enterprise bean [which would be an overkill] to validate the login data provided by the user. This could be called from the servlet which receives the request and needs to process it to decide the response [whether the user has logged on or not and the next page to be displayed accordingly]. The validation logic and/or some method(s) to retrieve user related data would be a part of the processing logic. This could be achieved in several ways, the least preferred and the most complicated being EJB. This could also be done by means of a bunch of plain Java objects with proper responsibilities.

Struts is a framework which provides some good features for developing web applications. I would suggest you to stay away from it till you get familiar with developing a simple web application using only servlet/jsp and some java beans [not EJB]. Having done that, you could proceed with other frameworks like Struts or Spring. I prefer Spring because it is almost a complete framework for enterprise applications, not just web applications.

I hope I was clear and I didn't toss in further confusions. :)