Passing variables through three pages - php

Question

I would like to pass variables through out three pages.
The method I am currently using is:
Fist Page has a form e.g. input type=”text” name=”username”
Second page receives input from form on first page with the $_POST function
e.g. $username=$_POST[“username”]
In order to keep the information from the first page stored, I created a session on the second page, and stored the input in it, e.g. as follows:
$_SESSION[“username”]=$username
I then navigate to the third page and start my session. If I echo the stored input from my session, the server returns “undefined variable username ”. I’m guessing this is so, because the variable $username is by definition $_POST[“username”], and in this case, there is no input for that post (being on the third page).
Of course I have tried converting the variable $username in a string and/or text with the print()/print_r() function. Doesn't change anything.
Does anyone have any solutions or workarounds to this issue?
I have come up with an unelegent way to solve the one problem: just recreate a copy of the form on the first page in the second page with the value=$_POST[“username”]…….but I need this to be a session, as these three pages are not linear (in other words, not steps 1,2,3, but steps 1,2,1,3 etc).
If it helps: this is a registration form (without passwords) with three pages. In the end, one must be able to navigate back to the pages to check ones inputs (so the data needs to be stored somewhere in order to call it up in the input fields).
Code page one (Inputs are in tables, left column specifies the what the Input is, right column the entry field):
<table>
<tr>
<td class="table_column_1"><p>Title </p></td>
<td>
<p><select name="title" class="dropdown" style="width:145px">
<option>Bitte waehlen</option>
<option value="Frau">Mr</option>
<option value="Herr">Mrs</option>
</select></p>
</td>
<tr>
<td class="table_column_1"><p>First name: </p></td>
<td><p><input type="text" name="firstname"</p>
</td>
</tr>
<tr>
<td><p>Surname: </p></td>
<td><p><input type="text" name="surname" /></p></td>
</tr>
<tr>
<td><p>Email: </p></td>
<td><p><input type="email" name="email" /></p></td>
</tr>
<tr>
<td><p>Company: </p></td>
<td><p><input type="text" name="company" /></p></td>
</tr>
<tr>
<td class="table_column_1"><p>Department: </p></td>
<td><p><input type="text" name="department" /></p></td>
</tr>
</table>
Code page two:
<?php
//Change variable to text/string
$title=print_r($_POST["title"]);
$firstname=print_r($_POST["firstname"]);
$surname=print_r($_POST["surname"]);
$email=print_r($_POST["email"]);
$company=print_r($_POST["company"]);
$department=print_r($_POST["department"]);
if ($title != "Bitte waehlen" && $firstname != "" && $surname != "" && $email != "" && $company != "" &&$department != ""){
session_start(1);
echo "Session: RUNNING";
//list for registration values
$_SESSION["registration"]="YES";
$_SESSION["title"]=$title;
$_SESSION["firstname"]=$firstname;
$_SESSION["surname"]=$surname;
$_SESSION["email"]=$email;
$_SESSION["company"]=$company;
$_SESSION["department"]=$department;
//Test session department and variable firstname validity
echo $_SESSION["department"];
echo $firstname;
}
else{
session_start(1);
$_SESSION["registration"]="NO";
echo "Session: NO";
header("location: registration.php");
};
?>
Code page three:
<?php
session_start(1);
echo "Session: RUNNING";
//Check if session department data is returnable => no
echo $_SESSION["department"];
?>

Answer 1

You'll have to show your code, but basically, this should work:
session_start();//before ANY output is sent to the client!
if (isset($_POST['username']))
{
$_SESSION['username'] = $_POST['username'];
}
if (!isset($_SESSION['username']))
{
//redirect, or present user with error message
}
$username = $_SESSION['username'];
This sets $_SESSION['username'] to the value of $_POST['username'] if that post value was sent, and assigns the value of $_SESSION['username'] to $username in all cases. if neither $_POST or $_SESSION have a username set, then there is an unexpected problem, and you should redirect, or show the user an error message...
After your code was posted, a couple of issues became obvious:
session_start expects no arguments, you're passing 1.
session_start can only be called when the headers haven't been sent (ie: no output), you're calling print_r, which creates output.
Don't use the closing ?> tag, if your script only contains PHP (see php.net if you want to know why)
Make sure there is no whitespace before the opening <?php tag
Functions return values for a reason: session_start returns false if the session couldn't be created: check return values
This means that your page2.php script should look like this, more or less:
<?php
if (!session_start())
exit('Output has already been sent!');//check for whitespace, use output buffering...
if (isset($_POST['title']) && $_POST['title'] !== 'Bitte waehlen')
{
$_SESSION['title'] = $_POST['title'];
$_SESSION["registration"]="YES";
//avoid notices, always use isset:
$_SESSION['firstname'] = isset($_POST['firstname']) ? $_POST['firstname'] : null;
}
else
{
//form wasn't submitted, or the title was "Bitte waehlen":
// show error message, or redirect
}

Answer 2

As far as I can understand you are using register globals.
Now that is your first error. Don't use it. Just don't.
Then, you are storing the username in a session, so now you can access it using
$_SESSION['username']
Also, when storing data in a session you also need to call session_start(); before assigning any data to your session.