Checking which radio button was clicked on a cck form using Javascript or Jquery

Question

I have a content type which I am loading in a block as a form. I am looking to know which radio button out of 2 buttons was clicked so that I can display additional fields. What is the best way to achieve this using JavaScript?

<div class="form-item">
 <label>I am: <span class="form-required" title="This field is required.">*</span></label>
 <div class="form-radios"><div class="form-item" id="edit-field-org-or-part-value-organizer-wrapper">
 <label class="option" for="edit-field-org-or-part-value-organizer"><input type="radio" id="edit-field-org-or-part-value-organizer" name="field_org_or_part[value]" value="organizer"   class="form-radio" /> Organizer</label>
</div>
<div class="form-item" id="edit-field-org-or-part-value-participant-wrapper">
 <label class="option" for="edit-field-org-or-part-value-participant"><input type="radio" id="edit-field-org-or-part-value-participant" name="field_org_or_part[value]" value="participant"   class="form-radio" /> Participant</label>
</div>
</div>
</div>

Answer 1

You can try .change() But you should haver the radio button under the same div.

I've used it in drupal 7

function foo() {
var field = $('#YOURFIELD').val();
  alert(field);
}

$('#YOURFIELD').change(foo);

Read this http://api.jquery.com/change/ to know more about .change()

Answer 2

If you want to have an 'other' type of field you could use: http://drupal.org/project/select_or_other

I maintain custom code to achieve what you want (on very long fake multistep forms) and don't recommend this, it quickly becomes very unmanageable.