How do I enable the Textbox using jquery which has been locked by radio buttons in php

Question

I have two radio buttons say "yes" and "no" when i click "yes" the text box will be enabled. But for some reason Radio buttons are hidden in this form and no is the default.

So i have a condition in php such as

so If the "Code" variable doesnot Exists in the "arr" then we show radio buttons and by clicking "yes" we have the juery functions which enables the textbox

if code Variable exists in the array then we dont display the radio buttons but the default is "no" which has been checked so the text box is disabled

if(!in_array($code,$arr)){
   enable radio buttons
}

I have to enable the textbox but the radio buttons are hidden