[Resolved] registered sessions and browser back button

[sgtpepper]

Hello Everyone!

I have created a multipage form that stores variables in a session. For example: page1.php has a few questions...click next page 2 has a few more...and all the answers are stored in a session like this:
session_register("VARIABLENAME");

Here is the problem...lets say a user answers questions on page 2. The variables (answers) that he gave are registerd once he click on the next button to go to page 3.

Now, he decides he made a mistake and clicks on his browsers back button to change page2.

Because the variable is already registered...his change is not accepted.

How can I allow a change made to be registered?

[LordShryku]

Could just do a check before registering the session variables to see if they're already set.

if(isset($_SESSION['var'])) {
   unset($_SESSION['var']);
}
$_SESSION['var'] = "blah";

[sgtpepper]

I am currently registering sessions like this:

session_register("AgentID");

So, are you saying I need to replace the above with

if(isset($SESSION['AgentID'])) {
unset($SESSION['AgentID']);
}
$_SESSION['AgentID'] = "AgentID";

[LordShryku]

No, you can use the same method, though you should read the comments on the [man]session_register[/man] manual page about register_globals. The converse check would be [man]session_is_registered[/man] and [man]session_unregister[/man].