Well if your new at struts and all , I suggest you first acquaint yourself with the basics of struts first as to how we actualy get a particular JSP to display based on some result obtained from an action class.
You should be able to navigate from one jsp to another via struts Action ( either by form submits or button clicks ). Next , look at how you can work with AJAX to trigger these struts actions asynchronously. I will recommend using Jquery to trigger ajax events. ( relatively easy )
Take it one step at a time. First, get to know struts.
Do post back for any queries and questions. We will surely help you along the way.