Disable, Enable Tickboxes

Hi All,

Wondering if you could point me in the right direction.

I have a form with questions etc that is being submitted via a simple formmail script and within the form are some questions that I would like folks to answer.

I want one part of the form to have a rating form, however I only want people who have experienced the service to respond.

I would like to have the rating checkboxes disabled, and if they tick a Yes form, the all the rating (Likert Scale) boxes become enabled to allow them to rate the service.

I thought of an onclick enable scenario, however it's not working because they scale is formatted in their own seperate cells so they look nice.
I also would like it to work across browsers, etc.

Cheers for any help you can pass my way,
Itchy