Nancy what I did was add this code to the radio buttons. I didn't save my PDF as dynamic, that was the problem I was having..
(make sure you keep the underscore - and with the click event right)
form1.pg1.formSection.bodySection._NewTextField.addInstance(1);
form1.pg1.formSection.bodySection._EditTextField.removeInstance(0);
form1.pg1.formSection.bodySection._EditTextField.addInstance(1);
form1.pg1.formSection.bodySection._NewTextField.removeInstance(0);
thanks for your help Nancy