The read only function does not work for radio buttons
2 answers
This is correct according to the standards:
w3.org/TR/html401/interact/forms.html#h-17.12.2
"The following elements support the readonly attribute: INPUT and TEXTAREA."
w3.org/TR/WD-forms-970402#readonly
"READONLY applies to INPUT elements of type TEXT or PASSWORD and to the TEXTAREA element."
You could have a look at this post which will do what you want it to do:
http://stackoverflow.com/a/15513256/1861389
regards