how to update quantity to calculate total price from price in php
<?php
$pro_id = $_COOKIE['product_id'];
$pro_id = explode(',', $pro_id);
$qua = 1;
foreach ($pro_id as $val) {
$ans = "SELECT * FROM wm_products WHERE pro_id='$val'";
$result = $conn->query($ans);
while($row = $result->fetch_assoc()){
?>
<tr class="cart_item">
<td>
<a href="single-product.html"><img src="products_images/<?php echo $row['pro_img']; ?>" alt="" width="180" height="180"></a>
</td>
<td>
<a href="single-product.html"><?php echo $row['pro_name']; ?></a>
</td>
<td>
<span class="amount">Rs. <?php echo $row['pro_price']; ?></span>
</td>
<td>
<div class="quantity buttons_added">
<form action="" method="post">
<input type="submit" class="minus" name="minus" value="-">
<input type="text" size="4" class="input-text qty text" title="Qty" value="<?php echo $qua;?>" name="" max="29" min="0" step="1" >
<input type="submit" class="plus" name="plus" value="+">
</form>
</div>
</td>
<td>
<span class="amount">Rs. <?php echo number_format($row['pro_price'] * $qua); ?></span>
</td>
<td>
<a class="remove remove_cart" href="#" dataid="<?php echo $row['pro_id']; ?>">×</a>
</td>
</tr>
<?php
}
}
?>