gistfile1.js

// Generates a click on the first element returned by document.querySelector("#foo")
// The main idea is to activate all the event handlers asociated to the node

// https://developer.mozilla.org/en/DOM/event.initMouseEvent
// http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-eventgroupings-mouseevents

click_event = document.createEvent("MouseEvents"); 
click_event.initMouseEvent("click", true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
document.querySelector("#foo").dispatchEvent(click_event);