Facebook Like birthday wishes

autolike-facebook-wishes.js

/**
 * Script to like all birthday wishes on timeline
 * By Piotr Pelczar
 * 
 * Usage:
 * 1. Activate programming console in Google Chrome (F12)
 * 2. Go to the console tab
 * 3. Expand all wishes list (see more) as it reach end
 * 4. Copy this script, paste and hit ENTER
 * 5. MAGIC HAPPENS!!! Massive amount POST like requests are sent to Facebook
 */

document.getElementsByClassName('contentAfter')[0].getElementsByClassName('UFILikeLink')

function eventFire(el, etype){
   if (el.fireEvent) {
     (el.fireEvent('on' + etype));
   } else {
     var evObj = document.createEvent('Events');
     evObj.initEvent(etype, true, false);
     el.dispatchEvent(evObj);
   }
}

for(var i = 0, j = a.length; i<j; ++i) if(a[i].title == 'Like this') eventFire(a[i], 'click');

Uncaught TypeError: Cannot read property 'getElementsByClassName' of undefined(…)