add multiple records from one form entry?

i would like to create a form that is able to enter multiple records (into the same form) at once.

e.g. in a form which has input variables x, y, and z, being able to put in x, y, and two z's, which would then add two records to the form ((x, y, z1) and (x, y, z2)).

is this possible?

i tried to do this by using on validate > input (into the same form) and then cancel submit of the original data (with two z's), but that didn't seem to work.