Attribute for Radio boxes in JS?

1

I’m trying to make a form validate, everything works fine expect the radio button part.

You can see I have “checked” for my radio button, what this does is check to see if the FIRST radio button is checked and that’s it, I need it to check to see if ANY of the radio buttons in the group is checked.

case 'textarea':
    if(f.value==''){cf_adderr(f)}							
break;
case 'checkbox':
    if(!f.checked){cf_adderr(f)}							
break;
case 'radio':
    if(!f.checked){cf_adderr(f)}							
break;
case 'select-one':
    if(!f.selectedIndex && f.selectedIndex==0){cf_adderr(f)}							
break;