Form question

I have several forms, which when submitted, send their data (: radio) to a function that is responsible for checking that all radios of that form in question are selected.

In the function, it is assigned to a variable which is the form in question (it comes from a function that checks which is the propagation of the event). I leave you a fragment of the function:

var validarRadios2 = function(data) {

    var formAValidar;

    if(data==1){
        formAValidar=elementosForm1;

    }else if(data==2){
        formAValidar=elementosForm2;

    }else if(data==3){
        formAValidar=elementosForm3;

    }else if(data==4){
        formAValidar=elementosForm4;

    }else{
        formAValidar=elementosForm5;

    }

    //var opciones = formAValidar.('radioButtons');
}

My question is: In the last line of code (which is wrong, but I guess it should be something similar to that), how can I select the radio buttons of a form that has been saved in a variable?!

I feel if it's a simple question, but I really do not know how it is done and I would really appreciate a help.