const myDiv = document.getElementById("myDiv");
const myButton = document.getElementById("myButton");


function decreaseWidth() {
  let width = myDiv.offsetWidth;
  if (width <= 0) {
    clearInterval(interval);
  } else {
    width--;
    myDiv.style.width = width + "px";
  }
}


myButton.addEventListener("click", function() {
  const interval = setInterval(decreaseWidth, 10);
});