I have two fields in a form, "site address" and "billing address".

I have a radio button, "same as site address", with one option, "yes"

I want to add an action on user input to this radio button so that if the option is selected then the text from the "site address" field is copied into the "billing address" field.

I'm sure this is simple but I can't seem to work it out. Can anyone help?

Thanks

Jeff