Validating multiple fields

[eluser]ReyPM[/eluser]
Hi, I have a form with multiple fields lets say:

Code:

input_name1, input_lastname1, input_email1
input_name2, input_lastname2, input_email2
input_name3, input_lastname3, input_email3
input_namen, input_lastnamen, input_emailn

All of them are in the same form but they are dynamic so "n" can take any value maybe is just one and one set of fields exists or maybe is two and two sets exists or maybe is 20 and 20 sets exists. See a set as a row or something like that. My question is: it's possible to validate all of them without know how many are?