How to jump to another form 'on success'

How to jump to another form 'on success'

Hi,

Pls excuse this newbie question (and I hope I'm in the right place) but I'm trying to work out how to open one form after completing another. What I want to do is this:

[list=]
fill out 'New Sale' form
On Success, open 'New Line Item' form with order number prepopulated
(Ideally) On Success (of New Line Item), provide option to add another line item (i.e. loop back) or finish


In this post I am particularly interested in getting step 2 to work, but more than happy to receive advice on step 3 also.

Thanks,
David