I have an onchange on a select list that generates an addbox. The currentbox is loaded the first time the page is loaded by pulling from the database. I want to only pull that one time, and each time the select list generates new results for the add box, I want the data inside of the current box to be sent to itself. Here's a diagram of the layout:

As you can see the arrows indicate that the items are to be moved from one list to the next, so it's basically a way to add new things to an object, or delete things from an object, but you can add several things to the object in different categories. When I want to change the categories of things to add I want the current list to remain intact.
Can someone please tell me a better way to do this, or how to send an associative array. As I said, I can send the array successfully, but when I get it from my $_POST variables, it sets the index to numeric. I'm also using the HTML notation for array. e.g. 'currentbox[]'
Help please

