const int PB = 5;
const int led = 4;
int ledstate = LOW;
int PreviousPBState;
int PresentPBState;
void setup(){
  pinMode(PB,INPUT);
  pinMode(led,OUTPUT);
}
void loop(){
  PresentPBState = digitalRead(PB);
  if(PresentPBState==HIGH){
digitalWrite(led, HIGH);
  }
  else{
    digitalWrite(led,LOW);
  }
}