Formulario de inscripcion

[Vicnaz]

Ya lo solucione de la misma manera que me pusiste tu! gracias!!!!

Aca dejo el codigo final:

Código Javascript:

function bloquear(){
var form = document.formulario;
if(form.sexo[0].checked){
    form.upa[0].checked = false;
    form.upa[1].checked = false;
    form.upa[2].checked = false;
    form.upa[3].checked = false;
    form.upa[4].checked = false;
form.upa[0].disabled = true;
form.upa[1].disabled = true;
form.upa[2].disabled = false;
form.upa[3].disabled = false;
form.upa[4].disabled = false;
}else if(form.sexo[1].checked){
    form.upa[0].checked = false;
    form.upa[1].checked = false;
    form.upa[2].checked = false;
    form.upa[3].checked = false;
    form.upa[4].checked = false;
form.upa[0].disabled = false;
form.upa[1].disabled = false;
form.upa[2].disabled = true;
form.upa[3].disabled = true;
form.upa[4].disabled = false;
}
}
 

Código HTML:

<form name="formulario" method="POST" action="contacto.php" onSubmit="return Validar(this);">
<label for="sexo">Sexo:<br>
Masculino<input type="radio" name="sexo" value="M" onclick="bloquear()">
Femenino<input type="radio" name="sexo" value="F" onclick="bloquear()"></label>

<br><br>

<label for"upa">Usted pertenece a:<br>
A<input type="radio" name="upa" value="A" disabled><br>
B<input type="radio" name="upa" value="B" disabled><br>
C<input type="radio" name="upa" value="C" disabled><br>
D<input type="radio" name="upa" value="D" disabled><br>
E<input type="radio" name="upa" value="E" disabled><br><br>
</label>
</form> 

Nuevamente gracias!!!