In following exemple, how can I do the "space bar pressed" action when i press enter button ?  

What I want is when I press enter, it will add a space, like when I press the space bar.  

```js
var textarea = document.getElementById("textarea");

textarea.onkeypress = function(){return (event.charCode >= 48 && event.charCode <= 57)||(event.charCode == 32);};
```

```css
textarea{
  height : 100px;
  width : 500px;
}
```

```html
<textarea id="textarea" placeholder="Here you can only press numbers and space bar !"></textarea>
```