void setup() {
  Serial.begin(115200);
  Serial.println("Setup-Start");
  // additional initialisation-code here
}

/*
1: program
2; go to chkflg
3: more program
20: chkflg
*/
void loop() { // 
  Serial.println("top of loop() executing 1: program");
  Serial.println("next thing entering function chkflg");
  chkflg(); // CALL of function with name "chkflg"
  Serial.println("going on after returning from function chkflg");
  Serial.println("3: more program");
  delay(3000); // BLOCKING delay which freezes microcontroller for 3 seconds
  Serial.println("bottom of loop()");
  Serial.println();
}


// declaring of the function 
void chkflg() {
  Serial.println("entering function chkflg which is 2; go to chkflg");
  Serial.println("c1");
  Serial.println("executing 2 chkflg");
  Serial.println("c2");
  Serial.println("exiting function with name chkflg");
}