calculating sum and parsing first table's variables to another page - php

Question

The Problem: Trying to calculate sum of a total variable which is inside the table invoicesub in the Form Process (2nd page). Trying to make the sum(total) appear in 3rd page which is display_invoice and also get the customer_name in the form process page(2nd page). somehow $_get["$cust_name"]; is not working and im getting a blank from it. Next, after i can get the sum_total variable how do i parse all these to the 4th page using a form?
Edit:http://imageshack.com/a/img19/8729/btls.png (picture of output)
http://imageshack.com/a/img20/8744/s3ut.png (picture of my database)
Too low rep, i cant post images. I uploaded it to image shack. The 1 on top of the table is from the mysqli_num_rows. This is the first row i entered in the form page. The 2nd row is missing
edit:
New Invoicefinal
echo "<table border='1'>\n";
echo "<tr>\n";
echo "<th>Services Rendered</th>\n";
echo "<th>Quantity</th>\n";
echo "<th>Price($)</th>\n";
echo "<th>Discount(%)</th>\n";
echo "<th>Amount</th>\n";
echo "</tr>";
$cname = $_GET["cname"];
global $connection;
$sql1="SELECT description,quantity, amount, discount, total, SUM(total) as sumtotal FROM invoicesub WHERE cust_name='$cname' GROUP BY description ORDER BY id";
$result2 = mysqli_query($connection, $sql1) or die(mysqli_error($connection));
echo $count;
while ($rows = mysqli_fetch_array($result2)){
echo "<tr>";
echo "<td>" . $rows['description'] . "</td>";
echo "<td>" . $rows['quantity'] . "</td>";
echo "<td>" . $rows['amount'] . "</td>";
echo "<td>" . $rows['discount']. "%" . "</td>";
echo "<td>" ."$". $rows['total'] . "</td>";
echo "</tr>";
}
echo "</table>";
?>
<?php
$sql1="SELECT SUM(total) as total_amt FROM invoicesub WHERE cust_name='$cname'";
$result3 = mysqli_query($connection, $sql1) or die(mysqli_error($connection));
while ($rows = mysqli_fetch_array($result3)){
echo "<tr>";
echo "<td>". "Total Amount:" ."$". $rows['total_amt'] . "</td>";
echo "</tr>";
echo "<form action=\"4thpage.php\" method=\"POST\">";
echo "<input type=\"hidden\" name=\"total_amt\"/>";
echo "Customer Paid:";
echo "<input type=\"text\" name=\"paid\" value=\"\"/>";
echo "<input type=\"submit\" name=\"submit\" value=\"Submit\"/>";
echo "<input type=\"button\" value=\"Cancel\" onclick=\"window.location='manage_content.php';\"/>";
echo "</form>";
}
The Form: It consists of a form that can allow more than 1 row of inputs, which means i will have more than 2 descriptions, quantity, amount and discount. Thus, i put them inside an array
Form Process: This is the 2nd page, it will take in all the arrays parsed in, make a loop to insert all the inputted variables in the form into the table invoicesub.
Display_invoice: This is the 3rd page, i want to show all the customer_name, descriptions, quantity, amount, total_amt that was keyed into invoicesub and then do a sum(total) and show it at the bottom of the page. I also want to insert the customer_name, sum(total) variable into the fourth page through the form at display_invoice. Is this possible?
Form
function addTextArea(){
count= count+1;
var div = document.getElementById('name');
div.innerHTML += "<div> <input type='text' name='name[]' value='' "+"id=name"+count+"> </div>";
div.innerHTML += "\n<br />";
var div = document.getElementById('quantity');
div.innerHTML += "<div><input type='text' name='quantity[]' value ='' "+"id=quantity"+count+"></div>";
div.innerHTML += "\n<br />";
var div = document.getElementById('amount');
div.innerHTML += "<div><input type='text' name='amount[]' value ='' "+"id=amount"+count+"></div>";
div.innerHTML += "\n<br />";
var div = document.getElementById('discount');
div.innerHTML += "<div><input type='text' name='discount[]' value ='' "+"id=discount"+count+"></div>";
div.innerHTML += "\n<br />";
}
function removeTextArea(){
document.getElementById("name"+count).remove();
document.getElementById("quantity"+count).remove();
document.getElementById("amount"+count).remove();
document.getElementById("discount"+count).remove();
count = count-1;
}
</script>
</head>
<body>
<form action="invoiceprocess.php" method="POST">
<?php
echo "<table border='2'>\n";
echo "<tr>\n";
echo "<th>Description</th>\n";
echo "<th>Quantity</th>\n";
echo "<th>Amount($)</th>\n";
echo "<th>Discount(%)</th>\n";
echo "</tr>";
echo "<tr>";
echo "<td>"?><input type='text' size="50" name='name[]' value='Examination and Consultation' readonly/><?php "</td>";
echo "<td>"?><input type='text' size="50" name='quantity[]' value='' /><?php "</td>";
echo "<td>"?><input type='text' size="50" name='amount[]' value='' /><?php "</td>";
echo "<td>"?><input type='text' size="50" name='discount[]' value='' /><?php "</td>";
echo "</tr>";
echo "<tr>";
echo "<td>"?><div id="name"></div> <?php "</td>";
echo "<td>"?><div id="quantity"></div> <?php "</td>";
echo "<td>"?><div id="amount"></div> <?php "</td>";
echo "<td>"?><div id="discount"></div> <?php "</td>";
echo "</tr>";
?>
Customer Name:
<br />
<input type="text" name="cust_name" value="" />
<br />
<input type="button" value="Add Description" onClick="addTextArea();">
<input type="button" value="Remove Description" onClick="removeTextArea();">
<input type="submit" name="submit" value="submit">
</form>
</body>
invoiceprocess (The 2nd page)
if (isset($_POST['submit'])){ // Process the form
$name_array = $_POST['name'];
$quantity_array = $_POST['quantity'];
$amount_array = $_POST['amount'];
$discount_array = $_POST['discount'];
$cust_name_array = mysql_prep( $_POST['cust_name']);
for ($i = 0; $i < count($name_array); $i++){
$cust_name = $cust_name_array;
$name = $name_array[$i];
$quantity = $quantity_array[$i];
$amount = $amount_array[$i];
$discount = $discount_array[$i];
$total_amt = ($amount - ($amount * ($discount / 100))) * $quantity;
global $connection;
$query = "INSERT INTO invoicesub (";
$query.= " cust_name, description, quantity, amount, discount, total";
$query.= ") VALUES (";
$query.= " '{$cust_name}', '{$name}', {$quantity}, {$amount}, {$discount}, {$total_amt}";
$query.= ")";
$result = mysqli_query($connection, $query);
}
redirect_to("invoicesubmitfinal.php?cname=".urlencode($cust_name));
}
Display_Invoice(invoicesubmitfinal.php)
echo "<table border='1'>\n";
echo "<tr>\n";
echo "<th>Customer_name</th>\n";
echo "<th>Description</th>\n";
echo "<th>Quantity</th>\n";
echo "<th>Amount($)</th>\n";
echo "<th>Discount(%)</th>\n";
echo "<th>Total_amt</th>\n";
echo "</tr>";
$cust_name = $_GET["$cust_name"];
global $connection;
$sql1="SELECT SUM(total) FROM invoicesub WHERE cust_name='$cust_name'";
$result2 = mysqli_query($connection, $sql1) or die(mysqli_error($connection));
while ($rows = mysqli_fetch_array($result2)){
echo "<tr>";
echo "<td>" . $rows['quantity'] . "</td>";
echo "<td>" . $rows['amount'] . "</td>";
echo "<td>" . $rows['discount']. "%" . "</td>";
echo "<td>" ."$". $rows['total'] . "</td>";
echo "<td>" . "$" . $total_amt . "</td>";
echo "</tr>";
<form action="insertfinal.php" method="POST">
Customer Paid:
<input type="text" name="paid" value="" />
</form>