checkbox as tables ?

Hi

I wrote a forms which has many checkboxes with the same name (name="Liczby[]").
I need to check in java how may checkboxes are checked on submit?

this is in form:
onsubmit="return Sprawdz(this)"

i tried to pass it with function

<script language="Javascript1.2">
<!--
function Sprawdz(formularz) {
var suma = 0;
for (i = 1; i < formularz.Liczby.length; i++)
if (formularz.Liczby[i].checked) { suma++ }
}
if (suma != 5) { return false }
else { return true }
}