Radio Button on edit remembers last choice would like it to no be Initial value none as per on add

Radio Button on edit remembers last choice would like it to no be Initial value none as per on add

Hi

Small Radio button issue

Radio two choices A / B (Initial value none)

On add select A

On edit A is selected (should be)

For On edit Would like neither A or B back to Initial value none

Any way to do this via script ?

thanks