If your host allows it,

webwiz — Mon, 05 Jan 2009 19:16:10 +0000

If your host allows it, Server Side Includes (SSI) is a simple solution.

There is a tutorial on Tizag

decibel.places — Sun, 04 Jan 2009 14:19:47 +0000

There is a tutorial on Tizag that explains what you want to achieve

You could also do it with a JavaScript file, but PHP is a better choice.

greg — Sun, 04 Jan 2009 12:48:02 +0000

The most common method is using a server side language such as PHP, and 'including' another file.

Something like "header.php" which would be all your most common used requirements (nav links etc) and can be included in each page as required.