// Pulse Function

var pulsePeriod = 1000;

window.addEvent('domready', function(){

	var doPulse = function(){
		var el = $(this);
		if($(el)){
			var state = el.retrieve('state');
			if(state){
				$(el).tween('opacity', '1.0', '0.5');
			}
			else{
				$(el).tween('opacity', '0.5', '1.0');
			}
			el.store('state', !(state));
		}
	}
	
	$$('.pulse').each(function(el){
		el.set('tween', {duration:1000});
		el.store('state',true);
		doPulse.periodical(pulsePeriod, el);
	});

});