Hi,
you can do this with just one script.
Check the setting of the radio button.
"yes" selected:
show the second form including hidden inputs with the values of the first form or store the values of the first form in a session and show the second form without hidden inputs.
"no" selected:
just send the mail
Second form submitted:
Take all the values (including the hidden field ones or the ones stored in the session) and send the mail.
Give the submit buttons different names like subfirst and subsecond.
In the script check if $POST['subfirst'] or $POST['subsecond'] has been submitted so you know what to do.
Use $_GET if the form method is set to GET.
Thomas