JSP error: class UserForm not found in class model.UserAction

etting the following error in the program..wat shod i do to remove this?I am using jdeveloper 10 g [code] package model; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.struts.action.*; import org.apache.struts.actions.DispatchAction; import org.apache.struts.actions.IncludeAction;

public class UserAction extends DispatchAction {

private final static String SUCCESS = "success";

public ActionForward add(ActionMapping mapping, ActionForm form,
        HttpServletRequest request, HttpServletResponse response)
        throws Exception {
    UserForm userForm = (UserForm) form;
    userForm.setMessage("Inside add user method.");
    return mapping.findForward(SUCCESS);
}

public ActionForward update(ActionMapping mapping, ActionForm form,
        HttpServletRequest request, HttpServletResponse response)
        throws Exception {
    UserForm userForm = (UserForm) form;
    userForm.setMessage("Inside update user method.");
    return mapping.findForward(SUCCESS);
}

public ActionForward delete(ActionMapping mapping, ActionForm form,
        HttpServletRequest request, HttpServletResponse response)
        throws Exception {
    UserForm userForm = (UserForm) form;
    userForm.setMessage("Inside delete user method.");
    return mapping.findForward(SUCCESS);
}

} [/code]