const int LED=3; //LED pin 
const int BUTTON=7; //imput pin where the button is connected
int val=0; //val is used to store the state of the input pin
int state=0; //0=LED is off and 1=LED is on


void setup() {
  pinMode(LED, OUTPUT); //informs arduino that the LED is an output
  pinMode(BUTTON, INPUT); //and button is imput
  // put your setup code here, to run once:

}

void loop() {
  val=digitalRead(BUTTON); //reads the input value and stores
  //verifies that the input has high value (button pressed) and changes the state value
  if (val==LOW) {
    state=1-state;
  }
  if(state==1){
    digitalWrite(LED, HIGH); //turn on the LED
  }else {
    digitalWrite(LED,LOW);
  }

  
  // put your main code here, to run repeatedly:

}