function timeAgo(num_seconds) {
	function numberEnding (number) {
		return (number > 1) ? 's ago' : ' ago';
	}
	if (num_seconds <= 0) {
		return 'just now!';
	}
	var years = Math.floor(num_seconds / 31536000);
	if (years) {
		return years + ' yr' + numberEnding(years);
	}
	var days = Math.floor((num_seconds %= 31536000) / 86400);
	if (days) {
		return days + ' day' + numberEnding(days);
	}
	var hours = Math.floor((num_seconds %= 86400) / 3600);
	if (hours) {
		return hours + ' hr' + numberEnding(hours);
	}
	var minutes = Math.floor((num_seconds %= 3600) / 60);
	if (minutes) {
		return minutes + ' min' + numberEnding(minutes);
	}
	if (num_seconds < 60) {
		return num_seconds + ' sec' + numberEnding(num_seconds);
	}
	return 'just now!';
}