example.js

// Needs an extra closure (not shown)

mode = {a: 'foo', b:'bar', c:'baz'}

for (var key in mode) {
          $('#' + key).change(function() {
          if ($(this).is(':checked')) {
                  mode[key] = true;
          }
          else {
                  mode[key] = false;
          }
  })
}