var changeHeight = function(selector, n) {
	$(function() {
		if (typeof n != 'number') {
			$(selector).flatHeights();
		}
		else {
			var sets = [], temp = [];
			$(selector).each(function(i) {
				temp.push(this);
				if (i % n + 1 == n) {
					sets.push(temp);
					temp = [];
				}
			});
			if (temp.length) sets.push(temp);

			$.each(sets, function() {
				$(this).flatHeights();
			});
		}
	});
};