Okay, ignore my post about temporary tables; this was a red herring! I am trying to create something akin to a shopping cart. I want someone to click on Order on one page and this data be stored, allowing them to add more and more items until they finally complete the transaction. I could see this as an array with a structure or type definition, if I were coding in VB or similar; but would be concerned about having an expanding array (not knowing how many transactions it would need to be holding). I could set a limit (say, create an array of 20; knowing that they are unlikely to order 20 items) but this could lead to failure. Equally, does PHP allow for the use of structure definitions (formerly I knew these as types)? What would be a good way of dealing with this issue? Is the session_id unique; never to be repeated? Could I use this within a purchase history table in the database to uniquely identify the current user's requests. There is no log in requirement here (final purchase is through PayPal) so there is no other Unique ID system. There are some nice potentials from this latter approach but what would you suggest?