int keyval;
int workid=0;
int push=0;
int btsw=2;
int ledR=11;
int ledB=10;
int ledG=9;
void setup() {
  // put your setup code here, to run once:
  pinMode(ledR, OUTPUT);
  pinMode(ledB, OUTPUT);
  pinMode(ledG, OUTPUT);
  pinMode(btsw, INPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  keyval=digitalRead(btsw);
  keyval=!keyval;
  
  Serial.print("keyval = ");
  Serial.println(keyval);  
  if (keyval==1){
    push=1;
  }
  if (keyval==0 && push==1){
    workid++;
    push=0;
    if (workid>3){
      workid=1;
    }
  }
  digitalWrite(ledR, LOW);
  digitalWrite(ledG, LOW);
  digitalWrite(ledB, LOW);
  
  Serial.print("workid = ");
  Serial.println(workid);
  Serial.println("===============");
  if(workid==1){
    digitalWrite(ledG, HIGH);
  }
  if(workid==2){
    digitalWrite(ledB, HIGH);
  }
  if(workid==3){
    digitalWrite(ledR, HIGH);
  }

delay(100);
}