[FX.php List] Problem with creating duplicate records

[Jerry Do]

Hello all,

I am new to fx.php and php.  I have problem users create duplicate records
by reload the response page.
For example:
I have a form name "formA" and the ACTION ="formA_response.php".
When the user click submit, the form will send all the information to
formA_response.php.
The formA_response.php page is the page to create new record.  I noticed
that if a user reload formA_reload.php,  new record will be created.  Is
there a good method to prevent the user reload the page or going to that
page?  
I am thinking that I might send to a page that will create the record then
close that page after the record created.  However, I am not sure it will
work or how to do write it yet.

Any input is welcome.

Thank you in advance,