I have created a solution like roberkules' solution, except mine clears the radiobutton if you click the radiobutton itself while it's checked. Use this if you don't want to add an extra "Clear" button to your layout.
http://jsfiddle.net/P9zZQ/6/
// Requires JQuery 1.4+ (possibly earlier)
$(function () {
// Turn off a radiobutton if clicked again while on
var checkOff = function (event) {
var target = $(event.target);
if (target.is('label')) {
// deal with clicked label
if (target.attr('for')) {
// label has 'for' attribute
target = $('#' + target.attr('for'));
} else {
// label contains a radiobutton as a child
target = target.find('input[type=radio]');
}
}
if (target.is('input:checked[type=radio]')) {
event.preventDefault();
window.setTimeout(function () {
target.attr('checked', false);
}, 200);
}
}
// Find all radiobuttons and labels inside .radio-clearable containers
$(
'.radio-clearable input[type=radio], ' +
'.radio-clearable label').mousedown(function (event) {
// When clicked -- clear if it was checked
checkOff(event);
}).keydown(function (event) {
// When receiving space, escape, enter, del, or bksp -- clear if it was checked
if (event.which == 32 || event.which == 27 || event.which == 13 || which == 46 || which == 8) {
checkOff(event);
}
});
});
Usage: For any radiobutton you want to be clearable in this manner, wrap it in a container with class "radio-clearable".
The code is triggered by clicking or sending a key (Space, Escape, Enter, Del, BkSp) to the radiobutton element or to its label.