Resetting a pulsecount

Using Arduino Programming Questions
11

...it should do - but doesn't. Here's the whole code, but pulsecount does not reset to 0 above 50.

At the moment, I am generating the interrupt with a pull down resistor from interrupt 0 pin to gorund, then supplying 5V to the interrupt pin, each time I do it the pulsecount increments - only sometimes by more than one, I guess due to bounce.

volatile int pulsecount = 0;

void setup()
{
  Serial.begin(9600);
  attachInterrupt(0, trig, RISING); // din D2
}

void trig()
{
  pulsecount++; // adds a count to the variable pulsecount
}

void loop()
{
  Serial.println(pulsecount);
  delay(500); // wait .5s before updated serial monitor again
  if (pulsecount > 50)
  {
    pulsecount = 0;
  }
}