example.js

//
// Tracking of action's status
//
ActionStatus = {    
  flags: { completed: false },
  reset: function() { this.flags.completed = false; },
  update: function(flags) { this.flags = flags; },

  completed: function() {
    var flag = this.flags.completed;
    this.reset();
    return flag; 
  }
}

//
// Register actions for document
//
$(document).ready(function(){

  function toggle_assignment_elements() {
    // do something useful
    ActionStatus.update({completed:true});
  }

  $.each(['unassigned','assigned'],function(idx,css) {
    $('p.'+css+' :checkbox').
      click(toggle_assignment_elements);
  });

}

example_step.rb

#
# Note that i'm using cucumber and have mixed 
# Selenium::Client::Base into cucumber's world.
#
When /^I (uncheck|check) "(w+)"$/ do | label, check |
  checkbox = labelled_checkbox[label]
  if ( checkbox['checked'] and check=~/^u/ ) or ( checkbox['checked'].nil? and check=~/^c/ )
    click cbox.locator
    wait_for_condition 'selenium.browserbot.getCurrentWindow().ActionStatus.completed()'
  end
end