Stop Infinit Scroll !!!

[wikfx]

Hi all I have a menu I am trying to do I downloaded a sample .fla file from flashkit, anyway here is the code

//
center = slide1._y;
borderleft = center-slide1._height/6;
borderright = center+slide1._height/6;
speed = 80;
friction = 0.75

function slidemenu () {
slide1._y += speed;
speed *= friction;

if (slide1.hitTest(_root._xmouse, _root._xmouse, true)) {
speed += (center-_ymouse)/60
}

if (slide1._y>borderright) {slide1._y-=slide1._height/3 }
if (slide1._y<borderleft) {slide1._y+=slide1._height/3}
}


now the problem is I am trying to make the menu NOT infinit can someone please help !!!!

W i K