Request.setAttribute

Question

when the user click on the button, then go to servlet side to check the validation,if there is problem then will return msg by this method :
RequestDispatcher dispatcher = httpRequest.getRequestDispatcher("back.jsp");
          httpRequest.setAttribute("result", result);
          dispatcher.forward(httpRequest, httpResponse);
and then forward to the back.jsp
in the back.jsp
using ${result} to display the message
now, i would like to ask how and when to clear the result value when the user click on other button,
because the message still here when user click another button.

Answer 1

How about this: When the user clicks the other button, redo the validation check and return an empty string if it passes. Then have the JSP page not show any error message if the value is an empty string.