iframe auto resizing

body = document.querySelector("body > iframe").contentDocument.body;

html = document.querySelector("body > iframe").contentDocument.documentElement;

document.querySelector("body > iframe").style.width = Math.max( body.scrollWidth, body.offsetWidth, html.clientWidth, html.scrollWidth, html.offsetWidth ) + "px";

document.querySelector("body > iframe").style.height = Math.max( body.scrollHeight, body.offsetHeight, html.clientHeight, html.scrollHeight, html.offsetHeight ) + "px";