Conditional formatting for radio box

[Bradex]

Can I do conditional formatting of a field based on the radio box?

E.g. I have three radio buttons for three labels (Apple, Ball, Cat). The corresponding values which will be entered in the table for these are 1, 2, 3.
If Apple, is selected, I want another field (textbox1) to get active. How can I do it?

I have tried the following (keeping textbox1 disabled by default), but none of them is working:
radiobutton1=True
radiobutton1="1"
radiobutton1="Apple"
label1=True
label1="1"


label1="Apple"

[Bradex]

Found out the answer!

I have to use [frame1] ="1"

Here frame1, is the box containing all the radio buttons.