I am new in web application and I have a pl/sql package using web toolkit. When people submit credit card, the
page is hanging for the credit card validation through gateway, sometimes people cannot wait the process
complete and  they click on back button or refresh buttons on the page, then they get pay twice. How do I prevent double submission of credit card page?

Thank you in advance.

UP!

foreigner ??? understand chinese...


stupidly, if I get this work, I will let the gateway to remember the identification of each user or request! like use session id,or when a request come in,you assign a hidden token to it! and if the request url come from itself which means refresh,you ignore it!
database check is also necessary! you use some marks in your database to verify if the user has already been processed!

do not forget javascript! it's a good assistant for your implementation!

[ 本帖最后由 window2003 于 2008-2-4 10:04 编辑 ]

Thank you for your response.
Question?
   How do capture the session id? Thank you.

stupidly, if I get this work, I will let the gateway to remember the identification of each user or request! like use session id,or when a request come in,you assign a hidden token to it! and if the request url come from itself which means refresh,you ignore it!
database check is also necessary! you use some marks in your database to verify if the user has already been processed!

do not forget javascript! it's a good assistant for your implementation! [/quote]

happy china year!

mean this:
        HttpSession session = request.getSession();
        System.out.println(session.getId());

I am not sure???