php multipage input value session variable print - php

Question

please correct me here.
i have created multi page form where i want to pass data from each pages to final pages and then submit those on email. first one is apply.php, there are many input fields, but i have listed some of those, here when some enters passport number in passport field, i want this to be passed in everypage of the form and print this at couple of places on each page. here getting some issues when passing some of these fields.
this is first page ( apply.php )
<?php
// Start the session
session_start();
?>
<form name="search_form" method="post" onSubmit="return chk();" action="apply2.php">
<input name="passportno" id="passportno" type="text" maxlength="20" placeholder="Enter Passport No." size="43" >
<input name="birthdate" type="date" class="textBoxDashed" size="43" id="birthdate" datepicker="true" datepicker_min="01/01/1900" datepicker_max="21/11/2017" maxlength="10" datepicker_format="DD/MM/YYYY" isdatepicker="true" value="">
<input name="button1" type="submit" value="Continue">
this is apply2.php . here there is some issues, i am not able to find, as you can see below codes, i am able to print date of birth but not able to print passport no ( input from form1 ). Please correct where i am wrong here.
<?php
session_start();
$msg="";
////include("connect.php");
if (isset($_POST['button1']))
{
extract($_POST);
$code=strtolower($_POST['captcha_code']);
$sess=strtolower($_SESSION["code"]);
if ($sess==$code)
{
$appid=time().rand();
$result=mysqli_query($con,"select *from registration where email='$email'");
if (mysqli_fetch_row($result)>0)
{
?>
<script>
alert("This email is already exist");
</script>
<?php
}
else
{
$query="insert into registration values('$appid','$passportno','$birthdate','$email')";
if (mysqli_query($con,$query))
$msg="Data saved Successfully.Please note down the Temporary Application ID $appid";
else
echo "not inserted".mysqli_error($con);
if (!isset($_SESSION["appid"]))
{
$_SESSION["appid"]=$appid;
}
}
}
else
{
?>
<?php
}
}
?>
<form name="OnlineForm" method="post" onsubmit="return OnSubmitForm();" action="apply3.php">
<input name="applid" id="applid" value="<?php echo $_SESSION["appid"];?>">
<input type="hidden" name="birthdate" value="<?php echo $birthdate;?>"><b><?php echo $birthdate;?>
<input name="passportno" type="text" class="textBoxDashed" id="passportno" value="" size="43" maxlength="14" value="<?php echo $passportno;?>">
input name="sc" type="submit" class="btn btn-primary" id="continue" value="Save and Continue" onclick="document.pressed=this.name">

Answer 1

Don't use extract. Also do some checking to see if the data is set. As for not getting the the data try $_POST['passportno'] and if you want to pull the values and put them back into the input boxes simply use <?php echo isset($_POST['passportno'])?$_POST['passportno']:'' ?> to return nothing if it is not defined.
Also you need to do add some protection to your inputs.
You can add protection by using $passportno = mysqli_real_escape_string($con, $passportno);