[jQuery] how to make a easy show/hide menu by JQUERY

[大连毕业设计]

JUST LIKE MORE TOP OR LEFT MENU,

like the top menu like this:
http://golf-clubs.best-buys.cn

or left menu like this:
http://www.alibaba.com/

is it easy to do,
can it easy to just write one line or two line  codes do?
thanks