swap depth on buttons(scrolling gallery)

[certified]

hello,
i making a scrolling menu(gallery of images), i have made the images itself buttons in the scrolling movieclip(scrolls with a tween), and on release they stop at a certain frame and change their size, my problem is

1. when the button resize i want it to be in an upper level over the neighbour buttons, i used swap depth but it didn't work, is this because they are buttons???and if so is their another way to do what i want ??


2. i used (_currentframe) property to make the movieclip stop scrolling on release, but i thought it detects the frame i am on and stops at it but i have had to tell it (_currentframe + number), where number is a number that increase...on each button

3. is there a way to make the same effect on over not on release???

the code i am using on each button
but the number at(_currentframe+50)differs from button to another

on (release) {
_root.gallery.gotoAndStop(_currentframe+50);
nine._width = 400;
nine._height = 400;
nine.swapdepth(1);
_root.yy = nine.getDepth;//i used it to test swap depth but it returned [type Function]
}

thanks