Ubercart

Here is what I want to accomplish. I want to force a user to pick "yes" or "no" when asked if they want a gift card with their order which is very simple using attributes. But then, IF they pick yes, I want to force them to enter text into a text box for what they want the gift note to say.

Right now I can only make the text box always required or never required, also using an attribute. Is there a way to make this conditionally required?

Thanks
Justin