A post-at-will network dialoging system is a kind of dialog software which is provided with a post-at-will tag, and is composed of a recipient software, a recipient software installation component, a Microsoft IE browser, and a set of HTML tag naming rules in association with an operation of the recipient software. When sweeping dirt with a hand broom and ordinary dustpan, generally there is a small amount of dirt that cannot be swept into the pan. The bottom member includes at least one of a ferromagnetic material and a permanent magnet. The fourth lens element with negative refractive power has a concave object-side surface and a convex image-side surface. The device is easy to manufacture, provides a pre-metered single unit dose, it is relatively easy to use, and can be reusable or disposable.