Vertical menu sliding in


I am trying to achieve a sliding in menu by using javascript.

Here is an example of what i want to create:

first screen:
when moving the mouse over the left side it should expand to: and when moving mouse out or clicking an item the menu should slide back again.

I have found this on the web:
but it has two problems:
it is horizontal (and doesn’t seem easy to me to change this to vertical)
the “hit area” is the same when expanded
(the menu totally disappears atm but this is easy to fix when)

next one i found is this one: (one on the bottom)
it seems almost perfect but the problem here is it works with display:none; so everything disappears and i cannot keep a part remaining on the left.

I hope there is someone over here who is able and willing to help me out.