Nema17 and a4988

My code, but it's not working for me
`
#include <Stepper.h>

const int stepsPerRevolution = 200;
Stepper myStepper(stepsPerRevolution, 2, 3);

const byte PinBut = 0;
byte butLst;

enum { Idle, CW, CCW };
int state = Idle;

// -----------------------------------------------------------------------------
void loop ()
{
// process state
switch (state) {
case Idle:
break;

case CCW:
myStepper.step (-1);
break;

case CW:
myStepper.step (1);
break;
}

// check for button press
byte but = digitalRead (PinBut);
if (butLst != but) {
butLst = but;
delay (20); // debounce
if (LOW == but) {
if (CCW < ++state) // advance state
state = Idle;
Serial.println (state);
}
}
}

// -----------------------------------------------------------------------------
void setup () {
Serial.begin (9600);

myStepper.setSpeed (200);

pinMode (PinBut, INPUT_PULLUP);
butLst = digitalRead (PinBut);
}`