manage_cart.php

<?php
session_start();

    if($_SERVER["REQUEST_METHOD"]=="POST")
    {
        if(isset($_POST['Add_to_Cart']))
        {
            if(isset($_SESSION['cart']))
            {
                $myitems=array_column($_SESSION['cart'],'Item_Name');
                if(in_array($_POST['Item_Name'],$myitems))
                {
                    echo"<script>alert('Item Already Added');
                    window.location.href='addcart.php'</script>";
                }
                else
                {
                    $count=count($_SESSION['cart']);
                    $_SESSION['cart'][$count]=array('Item_Name'=>$_POST['Item_Name'],'Price'=>$_POST['Price'],'Quantity'=>1);
                    echo"<script>alert('Item Added');
                    window.location.href='addcart.php'</script>";
                }
            }
            else
            {
                $_SESSION['cart'][0]=array('Item_Name'=>$_POST['Item_Name'],'Price'=>$_POST['Price'],'Quantity'=>1);
                echo"<script>alert('Item Added');
                window.location.href='addcart.php'</script>";

            }
        }
        if(isset($_POST['Remove_Item']))
        {
            foreach($_SESSION['cart'] as $key=>$value)
            {
                if($value['Item_Name']==$_POST['Item_Name'])
                {
                    unset($_SESSION['cart'][$key]);
                    $_SESSION['cart']=array_values($_SESSION['cart']);
                    echo"<script>alert('Item Removed');
                    window.location.href='mycart.php'
                    </script>";
                }
            }
        }
    }
?>