A couple notes:

When checking the $$cart$,$ just validate the quantity inputs

As it$$s just a cart simulation using Javascript, it won$$t completely work without it$,$ so just test those inputs for content

If you are using a solution with Javascript, that$$s ok$!$ But the same stipulations would remain about checking the quantity inputs, you just won$$t have to manually add the years to that select element

Based on data passed to the server using the superglobal POST variable, process the data so that an invoice is produced similar to the results achieved in Project $2.$

Your script will then generate an invoice showing the correct number of