fading problem

[imity4]

i'm having trouble making this sub navigation fade in and out based on the mouse _y position. it's calling a simple function however, every time the _y pos changes it runs the function. i need it to run the function only when the mouse _y pos is in a specific area.

the navigation needs to hold the current place the user is in and allow them full access to the rest of the site.

i'm attaching the sample nav. any help or better ideas as to how i can resolve this would be a great help.


thanks,

imity4