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 to cart');
				window.location.href= 'menu.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 to cart');
					window.location.href= 'menu.php';
				</script>";
			}
		}
		else
		{
			$_SESSION['cart'][0]=array('Item_name'=>$_POST['Item_name'],'price'=>$_POST['price'],'Quantity'=>1);
			echo"<script>
				alert('Item added to cart');
				window.location.href= 'menu.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='menu.php';
				</script>";
				}
			}
		}
		if(isset($_POST['Mod_Quantity']))
		{
			foreach($_SESSION['cart'] as $key => $value)
			{
				if($value['Item_name']==$_POST['Item_name'])
				{
					$_SESSION['cart'][$key]['Quantity']=$_POST['Mod_Quantity'];
				echo"<script>
				window.location.href='menu.php';
				</script>";
				}
			}
		}
}

?>