I am trying to get this pacman animation to cycle through an array of images and reverse direction when it hits the edge of the page.

I tried debugging in Chrome and it gave me the following error

"cannot read properties of null (reading width)"

var pos = 0;
//pageWidth is the width of the webpage. This is later used to calculate when Pac-Man needs to turn around. 
const pageWidth = window.innerWidth;
//This array contains all the PacMan movement images
const pacArray = [
  ['./images/PacMan1.png', './images/PacMan2.png'],
  ['./images/PacMan3.png', './images/PacMan4.png'],
];

// this variable defines what direction should PacMan go into:
// 0 = left to right
// 1 = right to left (reverse)
var direction = 0;

// This variable helps determine which PacMan image should be displayed. It flips between values 0 and 1
var focus = 0;

// This function is called on mouse click. Every time it is called, it updates the PacMan image, position and direction on the screen.
function Run() {
  let img = document.getElementById('PacMan');
  let imgWidth = img.width;
  let pageWidth = window.innerWidth;
  focus = (focus + 1) % 2;
  direction = checkPageBounds(direction, imgWidth, pos, pageWidth);
  img.src = pacArray[direction][focus];
  if (direction) {
    pos -= 20;
    img.style.left = pos + 'px';
  } else {
    pos += 20;
    img.style.left = pos + 'px';
  }
}

setInterval(Run,200)




// This function determines the direction of PacMan based on screen edge detection. 
function checkPageBounds(direction, imgWidth, pos, pageWidth) {
 

  if (direction == 1 & pos + imgWidth > pageWidth) direction== 0;
  if (direction == 0 & pos < 0) direction == 1;
  
  
  //
  return direction;
}


module.exports = checkPageBounds;