help with fwd/backwrd buttons affecting other buttons

//finds current x pos and sets speed to new x pos
Movieclip.prototype.scrollme1 = function(xPos) {
    cX = this._x;
    difX = cX-xPos;
    this._x = cX-(difX/5);
};
Movieclip.prototype.scrollme2 = function(xPos) {
    cX = this._x;
    difX = cX-xPos;
    this._x = cX-(difX/6);
};
stop();
//variable starting value
arrayIndex = 1;
//timeline stopping postions
timeline1Xpos = new Array(0, 0, -760, -1520, 305);
//scrolling animation
timeline1.onEnterFrame = function() {
    this.scrollme1(timeline1Xpos[arrayIndex]);
};
stop();
//variable starting value
arrayIndex = 1;
//timeline stopping postions
timeline2Xpos = new Array(0, 0, -760, -1520, 305);
//scrolling animation
timeline2.onEnterFrame = function() {
    this.scrollme2(timeline2Xpos[arrayIndex]);
};
//buttons that scroll the timeline to specific x positions
//but1
controller_mc.but1.onRollOver = function() {
    this.frameHold = this._currentframe;
    this.gotoAndStop("over");
};
controller_mc.but1.onRollOut = function() {
    this.gotoAndStop(this.frameHold);
};
controller_mc.but1.onRelease = function() {
    arrayIndex = 1;
    for (var mc in this._parent) {
        var thisHold = this;
        if ((this._parent[mc] == thisHold) && (this._parent[mc]._name.indexOf("but") != -1)) {
            this._parent[mc].gotoAndStop("on");
        } else {
            this._parent[mc].gotoAndStop("off");
        }
    }
    this.frameHold = this._currentframe;
};
//but2
controller_mc.but2.onRollOver = function() {
    this.frameHold = this._currentframe;
    this.gotoAndStop("over");
};
controller_mc.but2.onRollOut = function() {
    this.gotoAndStop(this.frameHold);
};
controller_mc.but2.onRelease = function() {
    arrayIndex = 2;
    for (var mc in this._parent) {
        var thisHold = this;
        if ((this._parent[mc] == thisHold) && (this._parent[mc]._name.indexOf("but") != -1)) {
            this._parent[mc].gotoAndStop("on");
        } else {
            this._parent[mc].gotoAndStop("off");
        }
    }
    this.frameHold = this._currentframe;
};
//but3
//
controller_mc.but3.onRollOver = function() {
    this.frameHold = this._currentframe;
    this.gotoAndStop("over");
};
controller_mc.but3.onRollOut = function() {
    this.gotoAndStop(this.frameHold);
};
controller_mc.but3.onRelease = function() {
    arrayIndex = 3;
    for (var mc in this._parent) {
        var thisHold = this;
        if ((this._parent[mc] == thisHold) && (this._parent[mc]._name.indexOf("but") != -1)) {
            this._parent[mc].gotoAndStop("on");
        } else {
            this._parent[mc].gotoAndStop("off");
        }
    }
    this.frameHold = this._currentframe;
};
// 
//timeline forward and backward buttons
controller_mc.goForward.onRelease = function() {
    if (arrayIndex<3) {
        arrayIndex++;
    }
};
controller_mc.goBack.onRelease = function() {
    if (arrayIndex>1) {
        arrayIndex--;
    }
};