Oh man, how long do we have to continue this?
This plugin is not “a simple htm file”, it involves an image that you need to have in order to show the close button. Where is this image located in your example?
the pnotify code create html elements on your page and uses a CSS sheet to style those elements.
One of those elements requires a physical image file, which you have obviously not saved to your sever.
good luck to you sir.