Adding Easing to (both ends of) a Mouse-controlled sliding menu?

Hi, I really hope someone can help me with this

I have build a mouse-controlled sliding menu like the one on [color=#22229c]http://www.flashlevel.com[/color] (On their website they have 3 of them actually) My menu is just horizontal instead of vertical.
Does anybody know how to add easing in both ends of a menu? I use this script in frame 1:

fscommand(“allowscale”, “false”);
fscommand(“showmenu”, “false”);
fscommand(“fullscreen”, “false”);
xpicture = 0;
film = 300;
scrollmovement = 5;
picture_width = 705;
name = “”;
scroll = 1;

and this code in frame 2:

if (scroll == 1) {
xmouse = _xmouse-(film/2);
speed = (xmouse)/scrollmovement;
if (speed<0) {
speed = -(speed);
}
if (xmouse<0) {
xpicture = xpicture+speed;
}
if (xmouse>0) {
xpicture = xpicture-speed;
}
}

and in frame 3:

if (xpicture>0) {
xpicture = 0;
}
if (xpicture<-(picture_width-film)) {
xpicture = -(picture_width-film);
}
setProperty(“pictures”, _x, xpicture);

I hope someone can tell me how to do it. I can attach the fla, if someone would have a look at it.
thanks anyway
cheers Jonas