int buttonstate=0;
int lastbuttonstate=0;
int ledstate=LOW;
int buttonpin=2;
int bulbpin=12;
void setup(){
  pinMode(buttonpin, INPUT);
  pinMode(bulbpin, OUTPUT);
}

void loop(){
  buttonstate=digitalRead(buttonpin);
  if (buttonstate != lastbuttonstate){
    if(buttonstate == HIGH){
      ledstate = !ledstate;
      digitalWrite(bulbpin, ledstate);
    }
    delay(50);
  }
  lastbuttonstate = buttonstate;
}