broken millis logic

unsigned int buzzer = 6;
int relayPin = 5;
unsigned long int runTime;
unsigned long int restTime;
unsigned int val = 0;
unsigned long previousMillisRun = 0;
unsigned long previousMillisRest = 0;
boolean pwrOn = true;
unsigned long myMillis;

void setup() {
  pinMode(relayPin, OUTPUT);
  digitalWrite(relayPin, HIGH);
}

void loop() {
      runTime = 1000;
      restTime = 1000;
      // you forgot this.
      unsigned long myMillis = millis();

      // this code runs when millis reaches 1000 (or more)
      // because previousMillisRun is set to 0, and runTime is 1000.
      if (myMillis - previousMillisRun >= runTime && pwrOn == true)
      {
        // you store 1000
        previousMillisRun = myMillis;
        // turn the relay off
        digitalWrite(relayPin, LOW);
        // now you set your state variable to the opposite.
        pwrOn = false;
      }

      // guess what, this code executes IMMEDIATELY after the previous if-statement, BECAUSE
      // pwrOn is now false. AND previousMillisRest is STILL 0!
      if (myMillis - previousMillisRest >= restTime && pwrOn == false)
      {
        // so you store the same 1000 value
        previousMillisRest = myMillis;
        // turn the relay back on
        digitalWrite(relayPin, HIGH);
        // and re-enable the first if-statement.
        pwrOn = true;
      }
// one second later, it happens again.
}