Jquery Disabling Input Not Working

I have some input elements on a page, and am trying to enable them or disable them according to the setting of a pair of radio buttons. I'm using the following Javascript function

Solution 1:

The answer to JQuery readOnly strange behavior explains your problem.

individual comes from a checkbox; it is a string. You have to cast it properly to a boolean:

$("#Surname").prop("disabled", (individual == "false" ? false : true));