How to submit form data to a database table in CodeIgniter

In my CodeIgniter project, one of my textbox field values is not inserting into db.

How to pass value from view to controller and vice-versa?

View Code (Here we enter the Ex-showromm Price,suppose 1500)

When we hit Bill button, the value has to enter into db and and print it as a bill.

<?php
$total = 0;     
$actual_price = 0;  
if (count($list_product) > 0) { 
    foreach ($list_product as $key => $item) {
        $total += $item['salePrice'];
        ?>
        <tr>
            <td bgcolor="#CCCCCC">&nbsp;<?= $item['model'] . "&nbsp;&nbsp;" . $item['variant'] ?>
                <br />&nbsp;<?= $item['vin'] ?> &nbsp;&nbsp;</td>
            <td bgcolor="#CCCCCC">&nbsp;
              <?= $item['saleQty'] ?></td>
            <td colspan="2" bgcolor="#CCCCCC"><input type="text" name="price" id="price" size="13px"/></td>
            <td colspan="2" bgcolor="#CCCCCC"><input type="text" name="actual_price" id="actual_price" size="13px"/></td>
        </tr>
        <?php
    }
}
?>
<tr>
    <td colspan="4" align="center" valign="middle" bgcolor="#E0DFE3" class="cont">&nbsp;<input name="tot_price" type="hidden" id="tot_price" size="50" value="<?=$total?>" /></td>
    <td colspan="4" align="center" valign="middle" bgcolor="#E0DFE3" class="cont">&nbsp;<input name="actual_price" type="hidden" id="actual_price" size="50" value="<?=$actual_price?>" /></td>

Bill View

The value from the database has been passed to a variable in the report

To pass a value to the view, you add it to an array and pass it to the view like so:

$Data['Pies'] = array('Cherry', 'Key Lime');
$Data['Cakes'] = array('Funfetti');
$Data['Paperplates'] = true;
$this->load->view('picnic', $Data);

CodeIgniter automatically unpacks the data on the view side, so you access it like so:

The first pie is <?=$Pies[0] ?>
<?php if ($Paperplates) { ?> 
    Don't bring plates <?php
} else { ?> 
    Bring plates please 
<?php }

will print:

The first pie is Cherry
Don't bring plates

Regarding returning values to the controller: you don't, at least not the way you're thinking. In order to get variables back you'll need them to be sent from the browser using a POST or GET request.

I suggest you start off by reading the CodeIgniter User Guide.