Some applications rely on the existence of stylesheets.
For a graceful exit in the case of disabled stylesheets, we need to know if they are enabled or disabled. If the browser is Internet Explorer 4.0x, stylesheets cannot be disabled. However, if the user is running Navigator 4.0x, we must find out if they are disabled by checking the existence of an element. IE4 is true when the Internet Explorer version is 4 and up as well. Learn more about the application that uses this technique in Column 16, Dynamic Tooltips .