This is an example of limiting selection of a set of on/off components on Chargify hosted pages to select only a single component. This script can be utilized by adding it to your "Custom Javascript" on the "Hosted Pages Settings" found under the "Settings" tab. Example Video: http://cl.ly/2237413N071y/on-off-components-single-selection.mov

single-on-off-components.js

$(function() {
  var updatingCheckboxes = false,
      $components        = $('.component-checkbox');
  $components.change(function(e) {
    if(updatingCheckboxes) { return; }
    var $el     = $(this),
        checked = $el.attr("checked");
    if(checked) {
      e.preventDefault();
      updatingCheckboxes = true;
      $components.attr("checked", false);
      $el.attr("checked", true);
      updatingCheckboxes = false;
    }
  });
});