How to remove inner HTML content onchange

I created a form where a user selects options from a checkbox list. So when a user selects an option in the checkbox, I use a function to show the value of the input field using onchange within inner HTML. My question is, how do we remove that same inner HTML content if the user un-selects those options? So when the user toggles back and forth, it either appears or when un-selected, the value gets removed. Thanks

function functionOne() {
  var x = document.getElementById("wheels").value;
  document.getElementById("demo").innerHTML = x;

}

<input type="checkbox" id="wheels" onchange="functionOne()" value="feature 1">

<div id="demo"></div>