Page ExtensionDisplays a message based on the extension (like .html) of the web page. And, it is a breeze to add more file types to the script.
Simply click inside the window below, use your cursor to highlight the script, and copy (type Control-c or Apple-c) the script into a new file in your text editor (such as Note Pad or Simple Text) and save (Control-s or Apple-s). The script is yours!!!