How can we add javascipts of any small code in wordpress

hello,
if we want to add small html code which having image or other java scripts code which updates some news or data automatically. my question is how can we add that code in blog.
ie. see this blog www(.)cephas(.)net/blog/ and see right side menu (this is reference blog) now if owner want to add small code that is it possible? if yes than how?

 

You tray using text widget yet?

 

You can code just about anything you want into the sidebar by editing sidebar.php. To display javascript in a post you'll need some sort of ad management plugin (like Adsense Deluxe or a newer version.)