Re: Prevent Brower From Going Back To Credit Card Page

Using AJAX techniques you might try this:

They enter the credit card.
When they hit submit, you do NOT automatically submit the page.
Instead you issue an Ajax request (XMLHttpRequest) to the server with the
credit card data. 
The CGI program you call via that requests, takes the card number, stores it
someplace on your iSeries, and returns a key to that number. Probably a
32-byte MD5 Message Digest. That is the key to a file or user index that
holds the number.
Then you return that number to your browser within an XML, for example:
<?XML version="1.0" ?)
<CipherData>
 <ccnbr>1lk2j3h4knfkluasdhfiasnf103</ccnbr>
</cipherData>

Then you, using JavaScript set the field containing the credit card number
to the value returned in the CCNBR value. You may also want to set a hidden
field to some flag that says you did this conversion in case you want to
permit back and forth processing.
Then, while still in the javascript, you issue the normal form submit
method. This time the subsequent CGI programs use the message digest to
access the credit card number as needed. The history cache only contains the
message digest which is worthless to hacks.


-Bob Cozzi
www.RPGxTools.com
RPG xTools - Enjoy programming again.


-----Original Message-----
From: web400-bounces@xxxxxxxxxxxx [mailto:web400-bounces@xxxxxxxxxxxx] On
Behalf Of Joe Giusto II
Sent: Wednesday, January 25, 2006 3:32 PM
To: web400@xxxxxxxxxxxx
Subject: [WEB400] Prevent Brower From Going Back To Credit Card Page

I am trying to prevent users from using the Back button in the web browser
to get back to the page where the credit card number was entered.  Or
alternatively, be able to erase that page from the history log or back
button log.

The closest I have come is with this JavaScript, which will throw the page
forward again when the user hits the back button.

</script><script
language="JavaScript">javascript:window.history.forward(-1);</script>

But does not prevent them from using the drop down arrow on the back button
to go back several pages to get to it.

I realize the script will work if I put it on each page, but I need to allow
them to go back and make changes until the final order page is accepted or
rejected.  That is when I write out a confirmation page with the script in
it.