How to add optional field only for certain selection

How to add an optional field for only selected part? This is the situation:

Registration information:
-Individual
-Group

If the user selected Group, then there will be automatically appear a few line of text box for user to put the group members name...

If the user selected Individual, nothing will be appear as the don't need to put anything...

Hi shah.sphere,

There is some code that may help you in this FAQ

Bob

Thanks for the feedback. I have try it, and it works.

The other problem now is about the e-mail template... As for the combo part, when it comes to the field that user don't need to fill in, then the e-mail template will appear their dynamic name for example:

Group: {group}

Is there any way to make it automatically hidden, if user didn't fill in the unrequired field?

Thank u!

Hi shah.sphere,

I've replied to this in another thread.

Please don't double post in the forums.

Bob