Interrupt change

Hi, I have a push button on pin 13 of a 328P. I've been using the following code to change interrupt:

volatile long ticks = 0;
long oldticks=0;

SIGNAL(PCINT0_vect) {
  ticks++;
}

void setup()
{
  Serial.begin(9600);
  digitalWrite(13,HIGH);
  pinMode(13, INPUT);
  PCMSK0 |= 32; 
  PCICR |= 1;
}

void loop() {
  if (ticks>oldticks)
  {
    oldticks=ticks;
    Serial.println("Interrupt");
  }
}

First question: Is the interrupt change needed or there is another label for PCINT0_vect that applies to pin 13? Second question: What do I need to change to get the same thing on 2560?

Thanks, RI

Well, I looked in the 2560 datasheet and answered my own question... the pin 13 on 2560 is actually PCINT7. So changing this: PCMSK0 |= 32; to this: PCMSK0 |= 128; did the trick.