Shopping Cart - Not Working

[Dysan]

On executing the code below, an error message appears. Why is this?

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\Documents and Settings\User\Desktop\Xampp\htdocs\cart.php on line 51

$total = 0;
echo '<table>';
foreach ($contents as $id=>$qty) {
$sql = 'SELECT * FROM books WHERE id = '.$id;
$result = mysql_query($sql);

$row = mysql_fetch_array($result);

echo '<tr>';
echo '<td><a href="cart.php?action=delete&id='.$id.'" class="r">Remove</a></td>';
echo '<td>'.$row['title'].' by '.$author.'</td>';
echo '<td>&pound;'.$price.'</td>';
echo '<td><input type="text" name="qty'.$id.'" value="'.$qty.'" size="3" maxlength="3" /></td>';
echo '<td>&pound;'.($price * $qty).'</td>';
$total += $price * $qty;
echo '</tr>';
}
echo '</table>';
echo '<p>Grand total: &pound;'.$total.'</p>';

echo writeShoppingCart();
echo '<a href="cart.php?action=add&id=1">Add to cart</a>';

[mikell]

my guess would be that the argument ($result) you are passing to the
mysql_fetch_array() function is not a valid MySQL result resource. Try using a valid one and I bet it will stop warning you.

[roscor]

Take a look at the post below by greensweater