Help with a scrolling flash panel

Question

Hello, Ive used the excellent tutorial to create a scrolling thumb panel (http://library.creativecow.net/articles/brimelow_lee/scrolling_thumbnail_panel/video-tutor ial.php)
It works brilliantly and I have movie thumbs linking to a flash player. It all works fine, what Im needing help with is to change the scrolling.
At current it scrolls up and down according to where I have set the 'line', I would like it to scroll up and down near the top and the bottom, rather than all the time (effectively creating a dead zone in the middle). I cant figure out how to change the code to get this to behave as required.
Please Help!
Below is the code used:
panel.onRollOver = panelOver;
function panelOver() {
this.onEnterFrame = scrollPanel;
delete this.onRollOver;
var b = stroke.getBounds(_root);
function scrollPanel() {
if(_ymouseb.yMax || _xmouseb.xMax) {
this.onRollOver = panelOver;
delete this.onEnterFrame;
if(panel._y >= 278) {   //FIRST BUTTON 'Y' POSITION
panel._y = 278;
if(panel._y <= -177) { //CHANGE '229' TO THE 'Y' POSITION OF THE LAST BUTTON IN THE 'PANEL' MOVIE, POSITIONED VISIBLE WITHIN THE BOARDERS.
panel._y = -177;
var ydist = _ymouse - 251; //POSITION ON STAGE OF UP/DOWN SCROLLING 'LINE'
panel._y += -ydist / 150;   //SPEED OF SCROLLING (LOWER = HIGHER)

Answer 1

use:
panel.onRollOver = panelOver;
function panelOver() {
this.onEnterFrame = scrollPanel;
delete this.onRollOver;
var b = stroke.getBounds(_root);
function scrollPanel() {
if(_ymouseb.yMax || _xmouseb.xMax) {
this.onRollOver = panelOver;
delete this.onEnterFrame;
if(panel._y >= 278) {   //FIRST BUTTON 'Y' POSITION
panel._y = 278;
if(panel._y <= -177) { //CHANGE '229' TO THE 'Y' POSITION OF THE LAST BUTTON IN THE 'PANEL' MOVIE, POSITIONED VISIBLE WITHIN THE BOARDERS.
panel._y = -177;
var ydist = _ymouse - 251; //POSITION ON STAGE OF UP/DOWN SCROLLING 'LINE'
if(_ymouse>lowerY || _ymouse<upperY){
if((_ymouse>lowerY){
ydist=_ymouse-lowerY;  // define lowerY
} else {
ydist=_ymouse-upperY;  // define upperY
} else {
ydist=0;
panel._y += -ydist / 150;   //SPEED OF SCROLLING (LOWER = HIGHER)