Not able to erase text entered in a behaviour set field in Unifier

Hello Friends,

 

Problem Description : 

We have a radio button (Y/N) as master element set and text field as a behavior set under it

when we select radio button Y field must get enabled and if 'N' field must get disabled

but suppose if initially customer select 'Y' and enter the some text but his mood changed and now he want to select radio button N

when he select N then the field got disabled but the text entered is still can see in read only mode.

We need to remove the entered text , is it possible in Unifier ?

Thanks,