After clicking the submit button in a form, everything became undefined - php

Question

Hi. Everything is working perfectly until I clicked the submit button.
This is what it looks like before clicking the submit button. But after clicking it, this is what it will look like. After clicking it, all the information became undefined. Can someone please help me.
I dont know what went wrong. Here is my code.
<?php
session_start();
if(!isset($_SESSION["user"]))
{
header("location:index.php");
}
ob_start();
include ('db.php');
$pid = $_GET['pid'];
$sql ="select * from reservation where reservationno = '$pid' ";
$re = mysqli_query($con,$sql);
while($row=mysqli_fetch_array($re))
{
$clientid = $row['clientid'];
$name = $row['name'];
$reservationno = $row['reservationno'];
$invoiceno = $row['invoiceno'];
$reservationdate = $row['reservationdate'];
$totalamount = $row['totalamount'];
$netamount = $row['netamount'];
$cin = $row['reservefrom'];
$cout = $row['reserveto'];
}
$asql ="select * from reservationdetails where reservationno = '$pid' ";
$are = mysqli_query($con,$asql);
while($row=mysqli_fetch_array($are))
{
$cout2 = $row['checkout2'];
$cout3 = $row['checkout3'];
$days = $row['days'];
$days2 = $row['days2'];
$days3 = $row['days3'];
$roomid = $row['roomid'];
$roomid2 = $row['roomid2'];
$roomid3 = $row['roomid3'];
$qty = $row['qty'];
$qty2 = $row['qty2'];
$qty3 = $row['qty3'];
}
?>
<div id="wrapper">
<nav class="navbar navbar-default top-navbar" role="navigation">
<div class="navbar-header">
<button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".sidebar-collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="home.php"><?php echo $_SESSION["user"]; ?> </a>
</div>
<ul class="nav navbar-top-links navbar-right">
<li class="dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#" aria-expanded="false">
<i class="fa fa-user fa-fw"></i> <i class="fa fa-caret-down"></i>
</a>
<ul class="dropdown-menu dropdown-user">
<li><i class="fa fa-user fa-fw"></i> User Profile
</li>
<li><i class="fa fa-gear fa-fw"> </i> Settings
</li>
<li class="divider"></li>
<li><i class="fa fa-sign-out fa-fw"></i> Logout
</li>
</ul>
<!-- /.dropdown-user -->
</li>
<!-- /.dropdown -->
</ul>
</nav>
<!--/. NAV TOP -->
<nav class="navbar-default navbar-side" role="navigation">
<div class="sidebar-collapse">
<ul class="nav" id="main-menu">
<li>
<i class="fa fa-dashboard"></i> Status
</li>
<li>
<i class="fa fa-desktop"></i> News Letters
</li>
<li>
<i class="fa fa-bar-chart-o"></i>Room Booking
</li>
<li>
<a class="active-menu" href="Payment.php"><i class="fa fa-qrcode"></i> Payment</a>
</li>
<li>
<i class="fa fa-qrcode"></i> Reports
</li>
<li>
</i> Logout
</li>
</div>
</nav>
<!-- /. NAV SIDE -->
<div id="page-wrapper" >
<div id="page-inner">
<div class="row">
<div class="col-md-12">
<h3 class="page-header">
Update Payment
</h3>
</div>
</div>
<!-- /. ROW -->`
<?php
include('db.php');
$mail = "SELECT * FROM `contact`";
$rew = mysqli_query($con,$mail);
?>
<div class="row">
<div class="col-md-12">
<div class="jumbotron">
<div class="panel-body">
<form>
<?php echo $clientid; ?><br>
<?php echo $name; ?><br>
Invoice no: <?php echo $invoiceno; ?><br>
Total Amount: ₱<?php echo $totalamount; ?><br>
Remaining Balance:
<br><br><br>
<h5>Payment: &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp<h5>
<input type="text" name="updatetextbox" /><br><br>
<h5>Confirm Payment:</h5>
<input type="text" name="updatetextbox1" />
<br>
<center><input type="submit" class="btn btn-primary" />
<?php
if(isset($_POST['submit'])){
$code1=$_POST['updatetextbox1'];
$code=$_POST['updatetextbox'];
if($code1!="$code"){
//$msg="Invalid code";
echo "<script type='text/javascript'> alert('Error')</script>";
}
else
$curdate=date("Y/m/d");
$paymentmode = "Cash";
$amountpaid_cash = 1.00;
$paymentdetails = "INSERT INTO `payments` (`clientid`, `name`, `reservationno`, `paymentmode`, `creditcardno`, `bankname`, `amountpaid_cc`, `amountpaid_cash`, `invoiceno`, `datepaid`) VALUES ('$clientid', '$name', '$reservationno', '$paymentmode', 'NULL', 'NULL', 'NULL', '$amountpaid_cash', '$invoiceno', '$curdate')";
if (mysqli_query($con,$paymentdetails))
{
echo "<script type='text/javascript'> alert('Your Booking application has been sent')</script>";
}
else
{
echo "<script type='text/javascript'> alert('Error adding user in database')</script>";
}
}
?>
</form>
</div>
</div>
</div>
<?php
$sql = "SELECT * FROM `contact`";
$re = mysqli_query($con,$sql);
?>
<!-- /. ROW -->
</div>
</div>
</div>
<!-- /. PAGE INNER -->
</div>

Answer 1

The problem is that you don't pass any of that information to the page after you submit it. Your first example shows pid as an HTTP get variable and that's what you use to define everything else. In your second example (after submit), there is no pid variable. Your code has no way to get the information unless you pass it along with the submit request or you include pid again, so that it can do the same lookup.

Answer 2

for those who came too late here is the answer to this question
you just need to put the insertion statement inside the :
This image will explain the solution
this happened because of the scope of the variables can't be reached outside the if statement block.