Scroll down menu

hi. need to locate a good tutorial for a menu to scroll down. but the ones i found are basic or start scrolling the other way.

i want the scroller to do 2 things
when ur cursor is down the bottom or at top of mask it moves the menu up and down.
then also a scroll bar on the side.

the problem is there are buttons in this menu and having the cursor over the bottom area may mean a invisible button on top of the menu....this will cause button layer problems?
let me know if any tutorials can help me please. cheers.