Selecting stored in variable

Hi I'm trying to create a shopping cart for a college assignment, I'm trying to load a table from the contents of a variable but regardless of what I do it won't recognise its contents.

Here the code snippet

$sql = sprintf("SELECT name, description, price FROM %s WHERE id = %d;",$table, $product_id);
$result = mysql_query($sql);


The table variables contents is being missed out so its looking a nameless table, I've searched Google and found a couple of examples but are working for me.

Does anyone have any ideas?

Thanks Scott.

---