object, through its
write( ) method, which we have already seen, allows you to write
arbitrary HTML into a document as the document is being parsed by the
browser. For example, you can include the current date and time in a
document or display different content on different platforms.
A cookie is a small amount of state data stored permanently or temporarily by the client. Cookies may be transmitted along with a web page by the server to the client, which stores them locally. When the client later requests the same or a related web page, it passes the relevant cookies back to the server, which can use their values to alter the content it sends back to the client. Cookies allow a web page or web site to remember things about the client -- for example, that the user has previously visited the site, has already registered and obtained a password, or has expressed a preference about the color and layout of web pages. Cookies help you provide the state information that is missing from the stateless HTTP protocol of the Web.
setTimeout( )is augmented by another useful method called
The Navigator object (named after the Netscape web browser, of course) has variables that specify the name and version of the browser that is running, as well as variables that identify the platform on which it is running. These variables allow scripts to customize their behavior based on browser or platform, so that they can take advantage of extra capabilities supported by some versions or work around bugs that exist on some platforms.