Let's assume your jsp is named login.jsp and that it has a corresponding form bean named LogonForm. In the "forwarding" Action instantiate an instance of Logon Form and then put it on the request (using setAttribute).
i.e. LogonForm logonForm = new LogonForm(); logonForm.setUserName("milton"); ... request.setAttribute("logonForm", logonForm); If your struts-config.xml has an action mapping with the bean name defined as "logonForm" and the form in your login.jsp forwards to this action mapping, then the fields will be "prefilled" using the form bean created in your calling action.