jQuery.fn.countdown = function(options) {
	if(!options) options = '()';
	if(jQuery(this).length == 0) return false;
	var obj = this;	

	if(options.seconds < 0 || options.seconds == 'undefined')
	{
		if(options.callback) eval(options.callback);
		return null;
	}

	window.setTimeout(
		function() {
			var sekundy = (options.seconds)%60;
			var minuty = Math.floor((options.seconds)/60);
			if((sekundy >= 0) && (sekundy < 10) ) {sekundy = '0'+sekundy;}
			jQuery(obj).html(String(minuty+':'+sekundy));
			--options.seconds;
			jQuery(obj).countdown(options);
		}
		, 1000
	);	

    return this;
}