Hi Jesse,
Please try the below JavaScript to achieve your scenario.
JavaScript:
function
DisableBox(sender, args) {
var
TextBox = $find(
"<%=txtSpouseName.ClientID %>"
);
if
(args.get_item().get_text() ==
"Married"
) {
TextBox.enable();
}
else
{
TextBox.clear();
TextBox.disable();
}
}
Thanks,
Shinu.