function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}

addLoadEvent(function() {
  
  $$('.effect').each(function (el) {
		return $(el).observe('mouseover', function() {
			el.addClassName('effectOver');
		});
	});
  $$('.effect').each(function (el) {
		return $(el).observe('mouseout', function() {
			el.removeClassName('effectOver');
		});
	});

  
});