Arrow MC following y axis of mouse

Hi,
I’m creating an interactive menu in Flash 5. As the user moves the cursor over a line of text a small arrow (movie clip) slides along the Y axis to the left of the menu as a visual aid to show which menu item is being selected.

Now, I’ve got this working using a small actionscript attached to the arrow:

onClipEvent (enterFrame) {
arrow = _root._ymouse-1-_y;
_y = _y+(arrow/4);
}

This works fine, but I need to change a few of things and being new to actionscripting, I’m at a loss.

Firstly, I need the Y movement of the arrow to stop at the top and bottom of the menu items. At the moment, if the arrow is moved beyond the menu, the arrow keeps moving. I need it to stop at the top item or the bottom item.

Secondly, I want the arrow to appear ‘sticky’…so that for instance, if the cursor is over the second line in the menu, the arrow sticks to a location on the Y axis (so it doesn’t slide around while the user is selecting a menu item). Once the cursor is moved from the second line to the third, the cursor then slides down until it ‘sticks’ to the third line. It’s hard to explain, but I hope you get the idea.

Finally, I want the arrow’s alpha to be 0% if the cursor rolls out of the flash window so it disappears when it isn’t needed. Obviously, when the cursor is brought back, the alpha needs to go back to 100% so the arrow ‘appears’ again.

I’ve enclosed the flash file so you can see what I’ve done so far. Any help on this would be really appreciated.

Ste.