transfering from one form to another

I am using VB express 2010. My question is this. I am creating a game similar to the old D&D games. I have a store on form1 in list box fashion. I have another form that just lists all of their equipment and allows them to change equipment or drop equipment. My problem is this. When they select an item from the store(listbox) how do I transfer that to the listbox on the equipment form. I also need to add equipment that is found while adventuring.

Thanks