js closes the browser window js closes the browser window without popping up the prompt box. Supports ie6, Firefox, Google and other browsers.
Firefox does not support js to close the browser window by default. You can change dom.allow_scripts_to_close_windows in about:config is true.
js checks the browser closing event js checks the browser closing or refreshing event and actively pops up a prompt box. Supports ie6, Firefox, Google and other browsers.