Validate two fields at the same time?

Hello all,
I have three fields (selects) in a form and I need to validate them in a particular way:
field1: mytype (values are 1 or 2);
field 2: myhour: (values are 00, 01, 02,..., 23);
field 3: mymin (values are: 00, 01, 02,...,59);

If I select 2 from field1 the validation would allow any value from field2 and field3.
But if I select 1 in field1, the values of field2 and field3 must be both '00' to pass validation.

Is there a way to do this?
Or, what is the best approach to solve this problem with WA tools?
TIA
tony

perhaps I found a solution:
I added a new rule to wa server validation sb:

Validation Type: Required...
Server variable: ((((isset($_POST["field2"]) && $_POST["field2"] != "00")) || ((isset($_POST["field3"]) && $_POST["field3"] != "00")) && ((isset($_POST["field1"]) && $_POST["field1"] == "1")))?"":$_POST["field1"])

It seems to work.
Is there a better way to do this?
TIA
tony

That seems like a perfect solution. Just like anything else there are multiple ways to accomplish this, but yours seems efficient and effective.