Drupal webform enabled fields

Question

I'm building form on my Drupal site using the Webform module and wanted to include some conditional questions.

The group of questions begins with a simple yes/no question. Depending on the answer of that boolean question, i'd like the questions after that to either carry on being disabled or become active for the user to answer. For example:

1. Do you have a Gas Certificate (Boolean) Yes/No

   1a. Start Date
   1b. End Date
   1c. Upload File [Upload]

Answer 1

You can either write your own js to do so or try using a module https://drupal.org/project/conditional_fields. I did use if for some other forms but not webform. Please try