Arduino + Accelerometer: Tilt Detection

iight guys here is the code...

int groundpin = 18; // analog input pin 4
int powerpin = 19; // analog input pin 5
int xpin = 3; // x-axis of the accelerometer
int ypin = 2; // y-axis
int zpin = 1; // z-axis (only on 3-axis models)
long xy_max = 470;
long xy_min = 550;

int forwardPin = 9;
int backPin = 10;
int leftPin = 11;
int rightPin = 12;
int centerPin = 8;

long x = 0;
long y = 0;

void setup()
{
Serial.begin(9600);

pinMode(forwardPin, OUTPUT);
pinMode(backPin, OUTPUT);
pinMode(leftPin, OUTPUT);
pinMode(rightPin, OUTPUT);

pinMode(groundpin, OUTPUT);
pinMode(powerpin, OUTPUT);
digitalWrite(groundpin, LOW);
digitalWrite(powerpin, HIGH);
}

void loop()
{

x = analogRead(xpin);
y = analogRead(ypin);
digitalWrite(centerPin, LOW);

if (y < xy_max) { //backwards

digitalWrite(backPin, HIGH);

Serial.println("The arduino is moving(tilted) backwards");

} else if (y >= xy_max){

digitalWrite(backPin, LOW);

}

if (y > xy_min) { //forwards

digitalWrite(forwardPin, HIGH);

Serial.println("The arduino is moving(tilted) forwards");

} else if (y <= xy_min){

digitalWrite(forwardPin, LOW);

}

if (x > xy_min) { //left

digitalWrite(leftPin, HIGH);

Serial.println("The arduino is moving(tilted) left");

} else if (x <= xy_min){

digitalWrite(leftPin, LOW);

}

if (x < xy_max) { //right

digitalWrite(rightPin, HIGH);

Serial.println("The arduino is moving(tilted) right");

} else if (x >= xy_max){

digitalWrite(rightPin, LOW);

}

if (y >= xy_max && y <= xy_min && x <= xy_min && x >= xy_max) { // nothing

digitalWrite(forwardPin, LOW);
digitalWrite(backPin, LOW);
digitalWrite(centerPin, HIGH);
digitalWrite(leftPin, LOW);
digitalWrite(rightPin, LOW);
Serial.println("The arduino is currently not moving(tilted) in any direction");
}
}