public  ActionForward processRequest(ActionMapping mapping, ActionForm form, HttpServletRequest req, HttpServletResponse res, ActionErrors errors) {

                String loginName = loginForm.getName();
		String password = loginForm.getPassword();

		// Set the target to failure
		 if  (!isAuthorized(loginName, password))
		{
			target = "failure";
			createErrorMessage(req, "login.error");
		}
}

 private   boolean  isAuthorized(String name, String password)
	{
		 boolean  result = true;
		 if  (name ==  null  || password ==  null  || name.length() ==  0  || password.length() ==  0 )
		{
			result = false;
		}
		// chech database
		 return  result;
	}

 private   void  createErrorMessage(HttpServletRequest req, String errorMsg)
	{
		ActionMessages msg =  new  ActionMessages();
		msg.add("error",  new  ActionMessage(errorMsg));
		 this .saveErrors(req, msg);
	}

<html:errors/>

 private   void  createErrorMessage(HttpServletRequest req, String errorMsg)
	{
		ActionMessages msg =  new  ActionMessages();
		msg.add("error",  new  ActionMessage(errorMsg));
		 this .saveErrors(req.getSession(), msg);		
	}