Sensor with ultrasound+2led+push button

Using Arduino LEDs and Multiplexing
1

Hello guys i'm starting programming and I need help for my project.
I need to know if something is not here and I press the button to turn on 1 led else the other led is turn on

atm I just know how to turn on 1 led with button and how to use sensor ultrasound.

void setup()
{
    Serial.begin(9600); //Initialisation de la communication avec le moniteur série
    pinMode(10,INPUT); //On indique à l’Arduino le mode du pin (entrée)
}
void loop()
{
    boolean a=digitalRead(10);// et on l’affecte à la variable "a"
    Serial.println(a); // on l'affiche sur le moniteur
}

and sensor ultrasound code

#define trigPin 13
#define echoPin 12
#define led 11
#define led2 10

void setup() {
  Serial.begin (9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led, OUTPUT);
  pinMode(led2, OUTPUT);
}

void loop() {
  long duration, distance;
  digitalWrite(trigPin, LOW);  // Added this line
  delayMicroseconds(2); // Added this line
  digitalWrite(trigPin, HIGH);
//  delayMicroseconds(1000); - Removed this line
  delayMicroseconds(10); // Added this line
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;
  if (distance < 4) {  // This is where the LED On/Off happens
    digitalWrite(led,HIGH); // When the Red condition is met, the Green LED should turn off
  digitalWrite(led2,LOW);
}
  else {
    digitalWrite(led,LOW);
    digitalWrite(led2,HIGH);
  }
  if (distance >= 200 || distance <= 0){
    Serial.println("Out of range");
  }
  else {
    Serial.print(distance);
    Serial.println(" cm");
  }
  delay(500);
}