I'm not sure this is the right place to put this in the forums,
as it's not just PHP related, but it is to do with application
design and I happen to be using PHP so here goes:  Does anyone
have any examples of coding HTML forms for handling one to many
relationships?  For example an invoice is a classic example of a
one to many data relationship where the invoice header (client
details, invoice date, etc) is on the one side and the invoice
detail lines (product being purchased, quantity, cost, etc) are
on the many side.  I know how to set this up on the database
side of things, I just haven't found a really good method of
handling this in HTML forms that let you easily and quickly add
/ change / delete invoice detail lines.  I guess that some AJAX
would come in handy here so that there's isn't lots of page
refreshing. I've looked at data grids in the past but most of
them seem to be set up to display and change lines of data but
not to quickly and easily add and delete lines.  Can anyone
point me in the dire