Scrolling horizontally

I just made a scroll area with buttons and draggable items. All the code is written for vertical scrolling, the content I need to be scrolled is going to be horizontal. how can I rewrite this code to be horizontal scrolling? it seems like the scroll button (the one you drag along) doesn’t stay confined to its scroll line either.

scrolling = function () {
var scrollHeight:Number = scrollTrack._height;
var contentHeight:Number = contentMain._height;
var scrollFaceHeight:Number = scrollFace._height;
var maskHeight:Number = maskedView._height;
var initPosition:Number = scrollFace._y=scrollTrack._y;
var initContentPos:Number = contentMain._y;
var finalContentPos:Number = maskHeight-contentHeight+initContentPos;
var left:Number = scrollTrack._x;
var top:Number = scrollTrack._y;
var right:Number = scrollTrack._x;
var bottom:Number = scrollTrack._height-scrollFaceHeight+scrollTrack._y;
var dy:Number = 0;
var speed:Number = 10;
var moveVal:Number = (contentHeight-maskHeight)/(scrollHeight-scrollFaceHeight);

scrollFace.onPress = function() {
var currPos:Number = this._y;
startDrag(this, false, left, top, right, bottom);
this.onMouseMove = function() {
dy = Math.abs(initPosition-this._y);
contentMain._y = Math.round(dy*-1*moveVal+initContentPos);
};
};
scrollFace.onMouseUp = function() {
stopDrag();
delete this.onMouseMove;
};
btnUp.onPress = function() {
this.onEnterFrame = function() {
if (contentMain._y+speed<maskedView._y) {
if (scrollFace._y<=top) {
scrollFace._y = top;
} else {
scrollFace._y -= speed/moveVal;
}
contentMain._y += speed;
} else {
scrollFace._y = top;
contentMain._y = maskedView._y;
delete this.onEnterFrame;
}
};
};
btnUp.onDragOut = function() {
delete this.onEnterFrame;
};
btnUp.onRollOut = function() {
delete this.onEnterFrame;
};
btnDown.onPress = function() {
this.onEnterFrame = function() {
if (contentMain._y-speed>finalContentPos) {
if (scrollFace._y>=bottom) {
scrollFace._y = bottom;
} else {
scrollFace._y += speed/moveVal;
}
contentMain._y -= speed;
} else {
scrollFace._y = bottom;
contentMain._y = finalContentPos;
delete this.onEnterFrame;
}
};
};
btnDown.onRelease = function() {
delete this.onEnterFrame;
};
btnDown.onDragOut = function() {
delete this.onEnterFrame;
};

if (contentHeight<maskHeight) {
scrollFace._visible = false;
btnUp.enabled = false;
btnDown.enabled = false;
} else {
scrollFace._visible = true;
btnUp.enabled = true;
btnDown.enabled = true;
}
};
scrolling();

I did the tutorial found here… http://www.kirupa.com/developer/flash8/scrollbar.htm