Picking Orders For Invoices

Hi everyone,

I'm sort of new to Access, but over the past few months I've been able to develop an inventory database for my work which turned out quite nicely and does everything I need it to, except for one thing.

I want to also create invoices for my customers, and after looking at examples I understand that most people link the "order" with the invoice, so that there is one invoice per order. However, I need the ability to combine many orders into one invoice. That's where I'm stuck.

I don't know how to arrange my relationships and forms so that I can "pick" the orders I want on my invoice, and not at the time of the Order, but at some point after. Basically my orders will be established, but their allocation to invoices won't, until I come along and put them into their rightful bill.

Does anyone have any thoughts on this? I'm pretty stumped.

Thanks a lot for your help.