insert multiple values in database - php

Question

I am new to php i'm trying to insert multiple values in database.I wrote my functions but it's throwing an error.I have attached my html form below.How can i solve this...
error showing:
A PHP Error was encountered
Severity: Notice
Message: Undefined index: itemNo
Filename: controllers/main.php
Line Number: 2406
My Code:
public function item_save(){
$con = mysql_connect("localhost","root","");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db("inventory", $con);
//$id_number = $_GET['id_user'];
$val1=$_GET['itemNo'];
$val2=$_GET['itemName'];
$val3=$_GET['quantity'];
$val4=$_GET['price'];
$val5=$_GET['total'];
$val6=$_GET['subTotal'];
$val7=$_GET['tax'];
$val8=$_GET['taxAmount'];
$val9=$_GET['totalAftertax'];
$val10=$_GET['amountPaid'];
$val1=$_GET['amountDue'];
$N = count($val1);
for($i=0; $i < $N; $i++)
{
mysql_query("INSERT INTO item_save(item_no,item_name,qty,price,total,subtotal,tax,tax_amount,total_final,amount_paid,amount_due) VALUES ('$val1[$i]','$val2[$i]','$val3[$i]','$val4[$i]','$val5[$i]','$val6','$val7','$val8','$val9','$val10','$val11')");
}
redirect("main/multiple");
}
form.html
<div class="container content">
<?php
echo form_open_multipart('main/item_save');
?>
<?php
$submit=array(
'name'=>'submit',
'type'=>'submit',
'class'=>'btn btn-primary',
'value'=>'Submit',
);
?>
<div class='row'>
<div class='col-xs-12 col-sm-12 col-md-12 col-lg-12'>
<table class="table table-bordered table-hover">
<thead>
<tr>
<th width="2%"><input id="check_all" class="formcontrol" type="checkbox"/></th>
<th width="15%">Item No</th>
<th width="38%">Item Name</th>
<th width="15%">Price</th>
<th width="15%">Quantity</th>
<th width="15%">Total</th>
</tr>
</thead>
<tbody>
<tr>
<td><input class="case" type="checkbox"/></td>
<td><input type="text" data-type="productCode" name="itemNo[]" id="itemNo_1" class="form-control autocomplete_txt" autocomplete="off"></td>
<td><input type="text" data-type="productName" name="itemName[]" id="itemName_1" class="form-control autocomplete_txt" autocomplete="off"></td>
<td><input type="number" name="price[]" id="price_1" class="form-control changesNo" autocomplete="off" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;"></td>
<td><input type="number" name="quantity[]" id="quantity_1" class="form-control changesNo" autocomplete="off" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;"></td>
<td><input type="number" name="total[]" id="total_1" class="form-control totalLinePrice" autocomplete="off" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;"></td>
</tr>
</tbody>
</table>
</div>
</div>
<div class='row'>
<div class='col-xs-12 col-sm-3 col-md-3 col-lg-3'>
<button class="btn btn-danger delete" type="button">- Delete</button>
<button class="btn btn-success addmore" type="button">+ Add More</button>
</div>
<div class='col-xs-12 col-sm-offset-4 col-md-offset-4 col-lg-offset-4 col-sm-5 col-md-5 col-lg-5'>
<form class="form-inline">
<div class="form-group">
<label>Subtotal: </label>
<div class="input-group">
<div class="input-group-addon">$</div>
<input type="number" class="form-control" id="subTotal" name="subTotal" placeholder="Subtotal" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
</div>
</div>
<div class="form-group">
<label>Tax: </label>
<div class="input-group">
<div class="input-group-addon">$</div>
<input type="number" class="form-control" id="tax" name="tax" placeholder="Tax" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
</div>
</div>
<div class="form-group">
<label>Tax Amount: </label>
<div class="input-group">
<input type="number" class="form-control" id="taxAmount" name="taxAmount" placeholder="Tax" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
<div class="input-group-addon">%</div>
</div>
</div>
<div class="form-group">
<label>Total: </label>
<div class="input-group">
<div class="input-group-addon">$</div>
<input type="number" class="form-control" id="totalAftertax" name="totalAftertax" placeholder="Total" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
</div>
</div>
<div class="form-group">
<label>Amount Paid: </label>
<div class="input-group">
<div class="input-group-addon">$</div>
<input type="number" class="form-control" id="amountPaid" name="amountPaid" placeholder="Amount Paid" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
</div>
</div>
<div class="form-group">
<label>Amount Due: </label>
<div class="input-group">
<div class="input-group-addon">$</div>
<input type="number" class="form-control amountDue" id="amountDue" name="amountDue" placeholder="Amount Due" onkeypress="return IsNumeric(event);" ondrop="return false;" onpaste="return false;">
</div>
</div>
</form>
</div>
<?php echo form_submit($submit);?>
</div>
</div>

Answer 1

Notice: Undefined index: itemNo means that your $_GET['itemNo']; is not set.
You probably forgot to add &itemNo=xxx in your URL, but looking to the rest of your code you are missing itemNo[] GET parameter from form (I guess checkboxes).
EDIT:
Now, after you posted HTML, and I still don't see <form> tag, let me ask you. Are you sure you are using GET method? Because multipart forms are usually using POST method.
Check your HTML output (as source code in browser), or some network debugging and check wether it's POST or GET. I bet that it's POST, but you try to retrieve GET.
Also, you can try change $_GET to $_REQUEST (matches both GET and POST), but that's not the best idea.