Two servos at once with millis

OK, I got both servos moving the amount I want them to move, but I need to reverse the right servo. I've tried for a few hours now and can't figure it out. Can someone help me to reverse it?

#include <Servo.h>

// --------CONSTANTS (won't change)---------------

const int onBoardLedPin   ;      // the pin numbers for the LEDs
const int led_A_Pin = 12;
const int led_B_Pin = 11;
const int buttonLed_Pin = 13;

const int buttonPin = 2; // the pin number for the button

const int onBoardLedInterval = 500; // number of millisecs between blinks
const int led_A_Interval = 2500;
const int led_B_Interval = 4500;

const int blinkDuration = 500; // number of millisecs that Led's are on - all three leds use this

const int buttonInterval = 300; // number of millisecs between button readings

const int leftServoPin = 9; // the pin number for the servo signal
const int rightServoPin = 10; // the pin number for the servo signal

const int leftServoMinDegrees = 90; // the limits to servo movement
const int leftServoMaxDegrees = 120;
const int rightServoMinDegrees = 90; // the limits to servo movement
const int rightServoMaxDegrees = 120;

Servo leftServo;
Servo rightServo;

//------------ VARIABLES (will change)---------------------

byte onBoardLedState = LOW;             // used to record whether the LEDs are on or off
byte led_A_State = LOW;           //   LOW = off
byte led_B_State = LOW;
byte buttonLed_State = LOW;


int leftServoPosition = 90;     // the current angle of the servo - starting at 90.
int leftServoSlowInterval = 50; // millisecs between servo moves
int leftServoFastInterval = 0;
int leftServoInterval = leftServoSlowInterval; // initial millisecs between servo moves
int leftServoDegrees = 1;       // amount servo moves at each step
// will be changed to negative value for movement in the other direction

int rightServoPosition = 90;     // the current angle of the servo - starting at 90.
int rightServoSlowInterval = 50; // millisecs between servo moves
int rightServoFastInterval = 50;
int rightServoInterval = rightServoSlowInterval; // initial millisecs between servo moves
int rightServoDegrees = 1;       // amount servo moves at each step
//    will be changed to negative value for movement in the other direction

unsigned long currentMillis = 0;    // stores the value of millis() in each
unsigned long leftPreviousServoMillis = 0; // the time when the servo was last moved
unsigned long rightPreviousServoMillis = 0; 

unsigned long previousOnBoardLedMillis = 0;   // will store last time the LED was updated
unsigned long previousLed_A_Millis = 0;
unsigned long previousLed_B_Millis = 0;

unsigned long previousButtonMillis = 0; // time when button press last checked


void setup() {

  pinMode(onBoardLedPin, OUTPUT);
  pinMode(led_A_Pin, OUTPUT);
  pinMode(led_B_Pin, OUTPUT);
  pinMode(buttonLed_Pin, OUTPUT);

  leftServo.write(leftServoPosition); // sets the initial position
  rightServo.write(rightServoPosition); // sets the initial position
  leftServo.attach(leftServoPin);
  rightServo.attach(rightServoPin);


  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {

  currentMillis = millis();   // capture the latest value of millis()
  //   this is equivalent to noting the time from a clock
  //   use the same time for all LED flashes to keep them synchronized

  readButton();               // call the functions that do the work
  updateOnBoardLedState();
  updateLed_A_State();
  updateLed_B_State();
  switchLeds();

  leftServoSweep();
  rightServoSweep();
}

void leftServoSweep() {    /////////////////////////////////////////////////////

  // nothing happens unless the interval has expired
  // the value of currentMillis was set in loop()

  if (currentMillis - leftPreviousServoMillis >= leftServoInterval) {
    // its time for another move
    leftPreviousServoMillis = leftPreviousServoMillis + leftServoInterval;  //increments leftServoInterval

    leftServoPosition = leftServoPosition + leftServoDegrees; // leftServoDegrees might be negative

    if ((leftServoPosition >= leftServoMaxDegrees) || (leftServoPosition <= leftServoMinDegrees))  {
      // if the servo is at either extreme change the sign of the degrees to make it move the other way
      leftServoDegrees = - leftServoDegrees; // reverse direction
      // and update the position to ensure it is within range
      leftServoPosition = leftServoPosition + leftServoDegrees;
    }

    // make the servo move to the next position
    leftServo.write(leftServoPosition);
    // and record the time when the move happened
  }
}

void rightServoSweep() {   //////////////////////////////////////

  // this is similar to the servo sweep example except that it uses millis() rather than delay()

  // nothing happens unless the interval has expired
  // the value of currentMillis was set in loop()

  if (currentMillis - rightPreviousServoMillis >= rightServoInterval) {
    // its time for another move
    rightPreviousServoMillis += rightServoInterval;

    rightServoPosition = rightServoPosition + rightServoDegrees; // servoDegrees might be negative

    if (rightServoPosition <= rightServoMinDegrees) {
      // when the servo gets to its minimum position change the interval to change the speed
      if (rightServoInterval == rightServoSlowInterval) {
        rightServoInterval = rightServoFastInterval;
      }
      else {
        rightServoInterval = rightServoSlowInterval;
      }
    }

    if ((rightServoPosition >= rightServoMaxDegrees) || (rightServoPosition <= rightServoMinDegrees))  {
      // if the servo is at either extreme change the sign of the degrees to make it move the other way
      rightServoDegrees = - rightServoDegrees; // reverse direction
      // and update the position to ensure it is within range
      rightServoPosition = rightServoPosition + rightServoDegrees;
    }

    // make the servo move to the next position
    rightServo.write(rightServoPosition);
    // and record the time when the move happened
  }
}

void updateOnBoardLedState() {

  if (onBoardLedState == LOW) {
    // if the Led is off, we must wait for the interval to expire before turning it on
    if (currentMillis - previousOnBoardLedMillis >= onBoardLedInterval) {
      // time is up, so change the state to HIGH
      onBoardLedState = HIGH;
      // and save the time when we made the change
      previousOnBoardLedMillis += onBoardLedInterval;
      // NOTE: The previous line could alternatively be
      //              previousOnBoardLedMillis = currentMillis
      //        which is the style used in the BlinkWithoutDelay example sketch
      //        Adding on the interval is a better way to ensure that succesive periods are identical

    }
  }
  else {  // i.e. if onBoardLedState is HIGH

    // if the Led is on, we must wait for the duration to expire before turning it off
    if (currentMillis - previousOnBoardLedMillis >= blinkDuration) {
      // time is up, so change the state to LOW
      onBoardLedState = LOW;
      // and save the time when we made the change
      previousOnBoardLedMillis += blinkDuration;
    }
  }
}

//========================================

void updateLed_A_State() {

  if (led_A_State == LOW) {
    if (currentMillis - previousLed_A_Millis >= led_A_Interval) {
      led_A_State = HIGH;
      previousLed_A_Millis += led_A_Interval;
    }
  }
  else {
    if (currentMillis - previousLed_A_Millis >= blinkDuration) {
      led_A_State = LOW;
      previousLed_A_Millis += blinkDuration;
    }
  }
}

//========================================

void updateLed_B_State() {

  if (led_B_State == LOW) {
    if (currentMillis - previousLed_B_Millis >= led_B_Interval) {
      led_B_State = HIGH;
      previousLed_B_Millis += led_B_Interval;
    }
  }
  else {
    if (currentMillis - previousLed_B_Millis >= blinkDuration) {
      led_B_State = LOW;
      previousLed_B_Millis += blinkDuration;
    }
  }
}

//========================================

void switchLeds() {
  // this is the code that actually switches the LEDs on and off

  digitalWrite(onBoardLedPin, onBoardLedState);
  digitalWrite(led_A_Pin, led_A_State);
  digitalWrite(led_B_Pin, led_B_State);
  digitalWrite(buttonLed_Pin, buttonLed_State);
}

//========================================

void readButton() {


  if (millis() - previousButtonMillis >= buttonInterval) {

    if (digitalRead(buttonPin) == LOW) {
      buttonLed_State = ! buttonLed_State; // this changes it to LOW if it was HIGH
      //   and to HIGH if it was LOW
      previousButtonMillis += buttonInterval;
    }
  }

}