int ledPins[]={2,3,4,5,6,7,8,9};

void setup() {

  int index;
  for(index=0;index<=7;index++)
  {
    pinMode(ledPins[index], OUTPUT);
  }
}

void loop() {
  marquee();

}
void marquee()
{
  int index;
  int delayTime = 200;
  for(index = 0; index <= 3; index++)
  {
    digitalWrite(ledPins[index], HIGH);  
    digitalWrite(ledPins[index+4], HIGH);  
    delay(delayTime);                      
    digitalWrite(ledPins[index], LOW);     
    digitalWrite(ledPins[index+4], LOW);   
  }
}