Display formatted JSON

[ampathdev]

I'm trying to create a page to show some JSON.
Something like this fiddle

I can get the JSON to display in a panel

<ext:Panel runat="server" Region="Center" Layout="FitLayout" Html="<pre id='someJson'></pre>">
...
document.getElementById("someJson").innerHTML = JSON.stringify(result, undefined, 4);

But it not formatted properly.