[Resolved] help $_SESSION undefined index and SID

chesterguyca

Hello,

I am pretty new to PHP and programming in general.

I am using the $SESSION variable and keep getting the error "undefinded index" after trying to reference a variable from a different page in my script.

After searching the forums and following the suggestions I was unable to find an answer to my issue. After going through the documentation I think I found the answer but am unsure becuase out of more than a dozen posts I did not see anyone even reference the function I used.

I am using IIS 5.0, and PHP 4.3.2, IE6sp1 and am accessing as "localhost"

If I run page1.php I get "undefined index error" unless, in the same window I open page1.php again by retyping the URL(back or reload wont work):

This does not work (it gives 'undefined index' error):

<?php
//page1.php
session_start();
$_SESSION['count'] =1;
header('Location: page2.php');
?>

<?
//page2.php
session_start();
echo $_SESSION['count'];
?>

This does work:

<?php
//page1.php
session_start();
$_SESSION['count'] =1;
header('Location: page2.php?' . SID . '');
?>

<?
//page2.php
session_start();
echo $_SESSION['count'];
?>

If I use a hyperlink to page2.php instead of header() the variables are also passed successfully.

Can anyone give me input on this? Does anybody have any more drawbacks or quirks when using header() . Any issues with using SID the way I did?

Should I just forget about using header()?

if you can give me good input on ANY of my questions I really appreciate it.

chesterguyca (thats %ca for Canada)

PS... And I hope this post also helps someone experiencing the same problem.

steadyguy

Have you tried using a link to go to the second page rather than a header() redirect? Also, have you tried it on a remote site? I find that I usually can't emulate the setup of the remote host exactly on my own box, so some things need to be uploaded and tested there ...

Also, I am unsure how it would work on an IIS server, but with Apache, the URL can be rewritten for you. I have never had problems with not getting the rewritten URL back in one piece ...

chesterguyca

I have tried <a href="page.php">click here</a>
and this works (it passes all the $_SESSION array correctly).

However, this requires a person to click on the hyperlink. There are situations where I want the refered link to open automatically will the $_SESSION array being passed correctly.

Should I be looking for another way to have the required window to automatically open?

Chesterguyca

steadyguy

Originally posted by chesterguyca
I have tried <a href="page.php">click here</a>
and this works (it passes all the $_SESSION array correctly).

However, this requires a person to click on the hyperlink. There are situations where I want the refered link to open automatically will the $_SESSION array being passed correctly.

Should I be looking for another way to have the required window to automatically open?

Chesterguyca

Maybe. You could also try passing the SID through the header() call:

header('Location: myscript.php?SID=' . SID);

Another option would be JavaScript ... but you'd still need to put a link on the page in that case, for people who don't have JS enabled.

chesterguyca

Steadyguy: What is the difference between the way that you passed the SID in the header and the way I passed the SID?

Your way:

header('Location: myscript.php?SID=' . SID);

My way:
header('Location: page2.php?' . SID . '');

steadyguy

Actually, I think I was a bit wrong, it should be

header('Location: myscript.php?PHPSESSID=' . SID);

That said, the difference is that the server doesn't know what that part of the URL means because it's not associated with any names. It might as well just be a random collection of numbers and letters.

chesterguyca

Strange, I did not put the "PHPSESSID=" part but it still worked.

thanks for help.

chesterguyca

steadyguy

Well, then. Both solutions work, eh? Good to know.🆒