$(document).ready(function() {
    $('.purr').not('.err').purr({
		fadeInSpeed: 500,
		fadeOutSpeed: 500,
		removeTimer: 4000,
		isSticky: false, 
    	usingTransparentPNG: true
    });
    $('.purr.err').purr({
    	isSticky: true,
    	usingTransparentPNG: true
    });
});