<div id="container">
</div>

<script>
// define functions
function createButton(caption, disabled) {
  let btn = document.createElement("button");
  btn.innerHTML = caption;
  btn.disabled = disabled;
  btn.style.width = "70px";
  btn.style.marginRight = "0.5em";
  return btn;
}

function enableButton(btn, enabled) {
  btn.disabled = !enabled;
}
</script>

<script>
// get container element, set style
let cnt = document.getElementById("container");
cnt.style.marginTop = "1em";

// create button elements
let btn1 = createButton("Default", false);
let btn2 = createButton("Simulate", true);
let btn3 = createButton("Display", true);
let btn4 = createButton("Download", true);
let btn5 = createButton("Reset", true);

// attach event handler
btn1.addEventListener("click", () => { enableButton(btn2, true); });
btn2.addEventListener("click", () => { enableButton(btn3, true); });
btn3.addEventListener("click", () => { enableButton(btn4, true); });
btn4.addEventListener("click", () => { enableButton(btn5, true); });
btn5.addEventListener("click", () => {
  enableButton(btn2, false);
  enableButton(btn3, false);
  enableButton(btn4, false);
  enableButton(btn5, false);
});

// add elements to container
cnt.append(btn1);
cnt.append(btn2);
cnt.append(btn3);
cnt.append(btn4);
cnt.append(btn5);
</script>