isAncestor and isDescendant

gistfile1.txt

	$.fn.isAncestor = function( elem ) {
		var $elem = $( elem );
		if (this.is( $elem )) {
			return false;
		}

		while (($elem = $elem.parent()).length) {
			if (this.is( $elem )) {
				return true;
			}
		}
		return false;
	};

$.fn.isDescendant = function( elem ) {
		return $(elem).isAncestor(this);
	};