form_set_error highlight offending field?

Question

form_set_error supposedly takes the name of the offending form element as the first param.

I have a form element that is named "field_reviewer_terms_of_service[value]" (as taken from firebug). My code that sets the error is:

    form_set_error('field_reviewer_terms_of_service[value]', t('You must agree to the Terms of Service.'));

The error shows up in the messages, but doesn't highlight the form element itself. What am I doing wrong?

Edited with HTML of form element:

<div id="edit-field-applicant-terms-of-service-value-wrapper" class="form-item">
 <label for="edit-field-applicant-terms-of-service-value" class="option"><input type="checkbox" class="form-checkbox required error" value="1" id="edit-field-applicant-terms-of-service-value" name="field_applicant_terms_of_service[value]"> I agree to the <a href="/terms_of_service" target="_blank">Terms of Service</a></label>
</div>

Answer 1

Don't put the [value] inside, it should work with only

form_set_error('field_reviewer_terms_of_service', t('You must agree to the Terms of Service.'));

See the documentation for form_set_error().
You may have to use some [value inside your field if it is multivalued, see this comment but we need to see the HTML ouput for your field.