I use the following code and I got error when I do appendChild

```
$('#tra').on('click', function() {
    transpile(source.val())

// ...
var display = $('#display');
diff.forEach(function(part) {

 var span = document.createElement('span');
        span.style.color = color;
        span.appendChild(document
            .createTextNode(part.value));
        display.appendChild(span);

```

In the last code I got error:

> 
> main.js:42 Uncaught TypeError: display.appendChild is not a function ,what it can be?
> 
> 
> 

in the index.html I've the display as follows