Arduino receiving imputs to steer servo and run dc-motor

#include <Servo.h>
#include <Wire.h>
#include <Adafruit_MotorShield.h>
#include "utility/Adafruit_MS_PWMServoDriver.h"

Adafruit_MotorShield AFMS = Adafruit_MotorShield();
Adafruit_DCMotor *myMotor = AFMS.getMotor(1);
Servo myservo;

int FWD = 0;
int BCK = 0;
int RGT = 0;
int LFT = 0;

void setup() {
  AFMS.begin();  // create with the default frequency 1.6KHz
  myMotor->setSpeed(0);
  myMotor->run(RELEASE);
  myservo.attach(10);  // attaches the servo on pin 10 to the servo object

  pinMode(4, INPUT);
  pinMode(5, INPUT);
  pinMode(6, INPUT);
  pinMode(7, INPUT);

  Serial.begin(9600);
}

int maxspeed = 100;

/*
    myMotor->run(RELEASE);
 myservo.write(90);
 */

void loop() {
  FWD = digitalRead(4);
  BCK = digitalRead(5);
  LFT = digitalRead(6);
  RGT = digitalRead(7);

  // ------ Forward routine ------
  if (FWD == 1 && BCK == 0){
    myMotor->run(FORWARD);
    myMotor->setSpeed(maxspeed);
  }

  // -------Backward routine ------

  if (BCK == 1 && FWD == 0){
    myMotor->run(BACKWARD);
    myMotor->setSpeed(maxspeed/2);
  }

  // ------ Release motor if no Forward of Backward input ------

  if (FWD == 0 && BCK == 0){
    myMotor->run(RELEASE);

  }

  // ------- Steer Left Routine --------

  if (LFT == 1 && RGT == 0){
    myservo.write(45);
  }

  // ------- Steer Right Routine --------

  if (RGT == 1 && LFT == 0){
    myservo.write(135);
  }

  if (LFT == 0 && RGT == 0 || LFT == 1 && RGT == 1 ){
    myservo.write(90);
  }


}