How do I connect the switch button to switch the animations ?

Guys i need help XD

I'm assembling an array with 5 MAX 7221 with Arduino, the Code provides a series of animations can be selected via a button, the problem is that I have no idea how I should connect the button sull'ARDUINO. Can you help me?

Here's the code I'm using.

thanks

//We always have to include the library
//File created for DragonCon 2011
#include "LedControl.h"
#include <Button.h>

// Change these pin numbers as neccessary
char Pin_dataIn = 9; // data in pin
char Pin_clk = 7; // clk pin
char Pin_load = 8; // load pin
char numOfMatrices = 5; // increment this for each 7219 you've got connected.  I imagine this will be 5.
int brightness = 8; // set the brightness of the LEDs.  Use a value between 0 - 15
char screen[40];
char screenSize = 40;

char textBuffer[3][100];
char textBufferSize[3] = {90,51,66};

int pointer = 0;
long nextFrameTime = 0;
int effectType = 0;
int framePointer = 0;

// init led control object
LedControl lc = LedControl(Pin_dataIn,Pin_clk,Pin_load,numOfMatrices);
Button button = Button(4, HIGH);

/* we always wait a bit between updates of the display */
unsigned int delayTime=40;

void setup() {
  
  /*
   The MAX72XX is in power-saving mode on startup,
   we have to do a wakeup call
   */
  for(int index=0;index<lc.getDeviceCount(); index++) {
    lc.shutdown(index,false);
    /* Set the brightness to a medium values */
    lc.setIntensity(index,brightness);
    /* and clear the display */
    lc.clearDisplay(index);
      
  }
  
  randomSeed(analogRead(0));
  button.setHoldDelay(3000);
  loadTextBuffers();
}



void loop() { 
  
  button.listen();
  
  if(button.onRelease()) {
    effectType++;
    
    if(effectType > 10) {
      effectType = 0;  
    }
    
    pointer = 0;
    framePointer = 0;
  }
  
  long current = millis();
  
  if(current > nextFrameTime) {
  
   nextFrameTime = current + delayTime; 
    
   switch(effectType) {
    case 0:
      effectThinLine();
      break;
    case 1:
       effectRandomPixels();
      break;
    case 2:
      effectScanner();
      break;  
    case 3:
      effectBlinkingEyes();
       break;
    case 4:
      effectTextScroll(0);
      break;
    case 5:
      effectTextScroll(1);
      break; 
    case 6:
      effectTextScroll(2);
      break;
    case 7:
      effectArrows();
      break;    
    case 8:
      effectECG();
      break;  
    case 9:
      effectScannerHorizontal();
      break;
    default:
      effectBlank();
      break;
  }

   display();
   
  }
   
}

void display() {
  
  unsigned char matrixID = 0;
  // screen now holds the updated values
  // write to the matrix
  for(unsigned char i = 0; i < numOfMatrices; i++) { 
    for(int j = 0; j < 8; j++) {
      
      int k = j;
       k += 1;
      if(k > 7) {
        k = 0;
      }
      
      char matrixID = 4 - i;
      //matrixID = 0;
      char bufferData = screen[((7-k)+(i*8))];
      char rowData = (bufferData >> 1) | (bufferData << 7);
     
      lc.setRow(matrixID,j,rowData);
    } 
  }
  
  /*
  for(unsigned char i = 0; i < screenSize; i++) {
   matrixID = floor(i/8);
    lc.setColumn(matrixID,i,screen[i]);
  }
  
   for(unsigned char i = 0; i < numOfMatrices; i++) { 
    for(unsigned char j = 0; j < 8; j++) {
      char matrixID = 4 - i;
      //matrixID = 0;
      lc.setColumn(matrixID,j,screen[(j+(i*8))]);
    }  
  }
  */
}

void scrollFromRight(int bufferNum) {
int offset = screenSize - pointer;
  for(unsigned char i = 0; i < screenSize; i++) {  
    screen[i] = getBufferData(bufferNum, i-offset);     
  }  
}

void scrollFromLeft(int bufferNum) {
int offset = (0-textBufferSize[bufferNum]) + pointer;
  for(unsigned char i = 0; i < screenSize; i++) {  
    screen[i] = getBufferData(bufferNum, i-offset);   
  }  
}

void staticCenter(int bufferNum) {
  int offset = round((screenSize - textBufferSize[bufferNum]) / 2);	
   for(unsigned char i = 0; i < screenSize; i++) {
    screen[i] = getBufferData(bufferNum, i-offset); 		
   }

}


char getBufferData(int bufferNum, int pos) {
    char tmp;
    if((pos >= 0) && ((pos) < textBufferSize[bufferNum])) {
      return textBuffer[bufferNum][pos];
    } else {
      return B00000000;
    }
}

void effectThinLine() {

  for(int i = 0; i < 40; i++) {
    screen[i] = B00011000;
  }
}  


void effectRandomPixels() {
  for(int i = 0; i < 40; i++) {
    screen[i] = random(256);
  }
}

void effectScanner() {
  for(int i = 0; i < 40; i++) {
    screen[i] = B00000000;
  }
  
  
  int tmpPointer = framePointer;
  
  if(framePointer > 37) {
    tmpPointer = 37 - (framePointer - 37);
  }
  
  for(int i = tmpPointer; i < (tmpPointer+3); i++) {
    screen[i] = B11111111;  
  }
  
  framePointer++;
  
  if(framePointer > 73) {
    framePointer = 0;
  }
  
}

void effectScannerHorizontal() {
  
   int tmpPointer = framePointer;
    
    if(framePointer > 6) {
        tmpPointer = 6 - (framePointer - 6);
     }
  
  for(int i = 0; i < 40; i++) {
    screen[i] = B10000000 >> (tmpPointer + 1);
  }
  
  display();
  delay(50);
  
  framePointer++;
  
  if(framePointer > 11) {
    framePointer = 0;
  }
  
}

void effectBlank() {
  for(int i = 0; i < 40; i++) {
    screen[i] = B00000000;
  }
}

void effectTextScroll(char bufferNum) {
   pointer += 1;
   
   if(pointer > (textBufferSize[bufferNum] + screenSize)) {
     pointer = 0;  
   }
   
   scrollFromRight(bufferNum);
}

void effectBlinkingEyes() {
  if(random(50) == 0) {