I am new to Javascript and learning to build a calculator as my first project. I don't understand why I am unable to get the value from the display to pass through the function via DOM. I've looked at other examples with a similar implementation, but don't understand why mine does not work. Can someone help explain this to me?

HTML:

```html
<form class="output-wrapper" name="output-wrapper">
  <input type="text" name="display" disabled>
  <div class="calc-btn-wrapper">
    <div class="nmb-btn container">
      <button type="button" value="1" onclick="calcfunc(1)">1</button>
      <button type="button" value="2" onclick="calcfunc(2)">2</button>
      <!-- ... -->
      <!-- ... -->
</form>

```

JavaScript:

```js
function calcfunc (num){
  var display = document.form['output-wrapper']['display'].value;
  if (display ==="" || display===0){
    let newvalu = display+num;
    document.form['output-wrapper']['display'].value=newvalu;
};

```