session problem

[swissbeets]

i just changed my form to have the values be hidden, rather than in my URL

this is the form

while($row = mysql_fetch_array($product_set))
{
?>
<form method="POST" action="shoppingcart.php">
  <input type="hidden" name="prod" value="<?php echo $row['product_id']; ?>" />
  <input type="hidden" name="action" value="add" />
  <p>
	<?php echo $row['product_name']; ?><br />
	$<?php echo $row['product_price']; ?><br /><br />
	<?php show_picture($row); ?><br />
	Size: 
	<p>
	  <select name="size">
         <?php
		$size = array('na'=>'Select','small'=>'S','medium'=>'M','large'=>'L','xlarge'=>'XL');
						showOptionsDrop($size, $active);
						?>
	  </select>
	</p> 
	<input type="submit" value="Add to Shopping Cart" />
  </p>
</form>
<?php
} 

 

these are then sent to my shopping cart but this is where the problem is, not only is the size not being saved in the function, the session is not allowing me to change anything, i cannot unset it to empty the cart or anything and anytime i add a new item the whole size says which ever size i chose

 

here is my code

 

$product_id = $_POST[prod];     //the product id from the URL
    $action     = $_POST[action]; //the action from the URL
 $size = $_POST['size'];

 echo $product_id;
 echo $action;
 echo $size;

    //if there is an product_id and that product_id doesn't exist display an error message
    if($product_id && !productExists($product_id)) {
        die("Error. Product Doesn't Exist");
    }

    switch($action) {    //decide what to do    

        case "add":
	 if ($size!="na"){
            $_SESSION['cart'][$product_id]++; //add one to the quantity of the product with id $product_id
		 //echo "success";
		} 
		else
		{
		echo "<br/>";
		echo "you did not choose a size for this item";
		?>
           <form method="POST" action="shoppingcart.php">
  <input type="hidden" name="prod" value="<?php echo $row['product_id']; ?>" />
  <input type="hidden" name="action" value="add" />
		<p>
	  <select name="size">
         <?php
		$size = array('na'=>'Select','small'=>'S','medium'=>'M','large'=>'L','xlarge'=>'XL');
						showOptionsDrop($size, $active);
						?>
	  </select>
         <input type="submit" value="Add to Shopping Cart" />
	</p> <?php

		 }

        break;

        case "remove":
            $_SESSION['cart'][$product_id]--; //remove one from the quantity of the product with id $product_id
            if($_SESSION['cart'][$product_id] == 0) unset($_SESSION['cart'][$product_id]); //if the quantity is zero, remove it completely (using the 'unset' function) - otherwise is will show zero, then -1, -2 etc when the user keeps removing items.
        break;

        case "empty":
            unset($_SESSION['cart']); //unset the whole cart, i.e. empty the cart.
        break;

    }


?>

 

 

     if($_SESSION['cart']) {    //if the cart isn't empty
         //show the cart
         echo "<table border=\"1\" padding=\"3\" width=\"40%\">";    //format the cart using a HTML table

             //iterate through the cart, the $product_id is the key and $quantity is the value
             foreach($_SESSION['cart'] as $product_id => $quantity) {   

                 //get the name, description and price from the database - this will depend on your database implementation.
                 //use sprintf to make sure that $product_id is inserted into the query as a number - to prevent SQL injection
                 $sql = sprintf("SELECT product_name, product_price FROM products WHERE product_id = %d;",
                                 $product_id);
                   
                 $result = mysql_query($sql);
                   
                 //Only display the row if there is a product (though there should always be as we have already checked)
                 if(mysql_num_rows($result) > 0) {
               
                     list($name, $price) = mysql_fetch_row($result);
               
                     $line_cost = $price * $quantity;        //work out the line cost
                     $total = $total + $line_cost;            //add to the total cost
               
                     echo "<tr>";
                         //show this information in table cells
                         echo "<td align=\"center\">$name</td>";
                         //along with a 'remove' link next to the quantity - which links to this page, but with an action of remove, and the id of the current product
                         echo "<td align=\"center\">$quantity <a href=\"$_SERVER[php_SELF]?action=remove&prod=$product_id\">Remove</a></td>";
                         echo "<td align=\"center\">$line_cost</td>";
					 echo "<td align=\"center\">$size</td>";
                   
                     echo "</tr>";

                 }
           
             }
           
             //show the total
             echo "<tr>";
                 echo "<td colspan=\"2\" align=\"right\">Total</td>";
                 echo "<td align=\"right\">$total</td>";
             echo "</tr>";
           
             //show the empty cart link - which links to this page, but with an action of empty. A simple bit of javascript in the onlick event of the link asks the user for confirmation
             echo "<tr>";
                 echo "<td colspan=\"3\" align=\"right\"><a href=\"$_SERVER[php_SELF]?action=empty\" onclick=\"return confirm('Are you sure?');\">Empty Cart</a></td>";
             echo "</tr>";       
         echo "</table>";
       
       

     }else{
         //otherwise tell the user they have no items in their cart
         echo "You have no items in your shopping cart.";

     }

 

 

 

 

please i feel like it is a only a few variables i am missing but any help is greatly appreciated