simple cart script session help

<?php
session_start();
$cart =& $_SESSION['wfcart']; // point $cart to session cart.
if(!is_object($cart)) $cart = new wfCart(); // if $cart ( $_SESSION['cart'] ) isn't an object, make a new cart
echo'<br><br><br>'; print_r($_SESSION['wfcart']);
$products = array();
$products[1] = array("id"=>1,"name"=>"Grey Name Badge","price"=>1.00);
$products[2] = array("id"=>2,"name"=>"Blue Name Badge","price"=>1.00);
$products[3] = array("id"=>3,"name"=>"Black Name Badge","price"=>1.00);
$products[31] = array("id"=>31,"name"=>"Drinks Coasters (box of 4)","price"=>9);
$products[32] = array("id"=>32,"name"=>"Mouse mats (5)","price"=>15);
$products[33] = array("id"=>33,"name"=>"Silver card wallets (10)","price"=>27.50);
$products[34] = array("id"=>34,"name"=>"Set of 3 books","price"=>33.00);


//start of code

    // check to see if any items are being added
if($_POST['add']) {
	$product = $products[$_POST['id']];
	$cart->add_item($product['id'],$_POST['qty'],$product['price'],$product['name']);
}
if($_POST['remove']) {
	$rid = intval($_POST['id']);
	$cart->del_item($rid);

}
if($_POST['email']) {
	// make email
	
	if($cart->itemcount > 0) {
	$message = "order form";
	$subject = $message;
	$emailfrom = "[email protected]";
	$emailto = "[email protected]";
	
	$message .= "\n\r\n\r";
	foreach($cart->get_contents() as $item) {
		
		$message .= $item['qty']." @ ";
		$message .= number_format($item['price'],2)." - ";
		$message .= $item['info']." = ";
		$message .= "£".number_format($item['subtotal'],2)."\n\r";
	}
	$message .= "---------------------\n\r";
	$message .= "Total: £".number_format($cart->total,2);
} else {
	$message .= "No items in cart";
}
	mail($emailto,$subject,$message,
			"From: ".$emailfrom."\r\n"."Reply-To: ".$emailfrom);	
			
	mail($emailto,"Copy of ".$subject,$message,
			"From: ".$emailfrom."\r\n"."Reply-To: ".$emailfrom);	
			
			
	$cart->empty_cart();
		echo"<h3>Thankyou your order has been submitted</h3>";


}

// spit some forms
// You can have many different types of forms, such as many quantity boxes
// and an "add to cart" button at the bottom which adds all items
// but for the purposes of this demo we will handle one item at a time. 
echo "<table width='100%'>";
foreach($products as $p) {
	$pricetext = "";
	if($p['price']<>0) $pricetext = "£".number_format($p['price'],2);
	echo "<tr><td><form method='post' action=''>"; // ****note this might need changing to your document alias to get it to work
	echo "<input type='hidden' name='id' value='".$p['id']."'/>";
	echo "".$p['name'].'</td><td>'.$pricetext."</td><td> ";
	echo "<input type='text' name='qty' size='5' value='1'></td><td><input type='submit' value='Add to order' name='add'>";
	echo "</form></td></tr>";
}
echo "</table>";


echo "<h3>Items in cart</h3>";

if($cart->itemcount > 0) {
echo "<table>";
	foreach($cart->get_contents() as $item) {
		echo "<tr><td>";
		echo $item['qty']." @ ";
		echo " £".number_format($item['price'],2)."</td><td>";
		echo $item['info']."</td><td>";
		echo "Subtotal :£".number_format($item['subtotal'],2)."</td><td>";
		echo "<form method=post><input type='hidden' name='id' value='".$item['id']."'/><input type='submit' name='remove' value='Remove'/></form></td></tr>";
	}
	
	echo "<tr><td> </td><td> </td><td>";
	echo "<b>Total: £".number_format($cart->total,2);
	echo "</b></td><td> </td></table>";
	echo "<form method=post><input type='submit' name='email' value='Submit Order by Email'/></form></td></tr>";
} else {
	echo "No items in cart";
}
echo'<br><br><br>'; print_r($_SESSION['wfcart']);
class wfCart {
	var $total = 0;
	var $itemcount = 0;
	var $items = array();
        var $itemprices = array();
	var $itemqtys = array();
        var $iteminfo = array();

	function cart() {} // constructor function

	function get_contents()
	{ // gets cart contents
		$items = array();
		foreach($this->items as $tmp_item)
		{
		        $item = FALSE;

			$item['id'] = $tmp_item;
                        $item['qty'] = $this->itemqtys[$tmp_item];
			$item['price'] = $this->itemprices[$tmp_item];
			$item['info'] = $this->iteminfo[$tmp_item];
			$item['subtotal'] = $item['qty'] * $item['price'];
                        $items[] = $item;
		}
		return $items;
	} // end of get_contents


	function add_item($itemid,$qty=1,$price = FALSE, $info = FALSE)
	{ // adds an item to cart
                if(!$price)
		{
		        $price = 0.00;
		}

                if(!$info)
		{
                        $info = wf_get_info($itemid);
		}

		if($this->itemqtys[$itemid] > 0)
                { // the item is already in the cart..
		  // so we'll just increase the quantity
			$this->itemqtys[$itemid] = $qty + $this->itemqtys[$itemid];
			$this->_update_total();
		} else {
			$this->items[]=$itemid;
			$this->itemqtys[$itemid] = $qty;
			$this->itemprices[$itemid] = $price;
			$this->iteminfo[$itemid] = $info;
		}
		$this->_update_total();
	} // end of add_item


	function edit_item($itemid,$qty)
	{ // changes an items quantity

		if($qty < 1) {
			$this->del_item($itemid);
		} else {
			$this->itemqtys[$itemid] = $qty;
			// uncomment this line if using 
			// the wf_get_price function
			// $this->itemprices[$itemid] = wf_get_price($itemid,$qty);
		}
		$this->_update_total();
	} // end of edit_item


	function del_item($itemid)
	{ // removes an item from cart
		$ti = array();
		$this->itemqtys[$itemid] = 0;
		foreach($this->items as $item)
		{
			if($item != $itemid)
			{
				$ti[] = $item;
			}
		}
		$this->items = $ti;
		$this->_update_total();
	} //end of del_item


        function empty_cart()
	{ // empties / resets the cart
                $this->total = 0;
	        $this->itemcount = 0;
	        $this->items = array();
                $this->itemprices = array();
	        $this->itemqtys = array();
                $this->iteminfo = array();
	} // end of empty cart


	function _update_total()
	{ // internal function to update the total in the cart
	        $this->itemcount = 0;
		$this->total = 0;
                if(sizeof($this->items > 0))
		{
                        foreach($this->items as $item) {
                                $this->total = $this->total + ($this->itemprices[$item] * $this->itemqtys[$item]);
				$this->itemcount++;
			}
		}
	} // end of update_total

}
?>

echo'<br><br><br>'; print_r($_SESSION['wfcart']);

error_reporting(0);