// Check if we're contained in a frame
const inFrame = window.self !== window.top;
// If we're not in a frame, load the frameset with the requested page in mainFrame.
if (inFrame == false) {
  document.getElementsByTagName('body')[0].outerHTML = `
			<frameset cols="200,*" frameborder="no">
				<frame src="/nav.htm" name="leftFrame" scrolling="yes" noresize>
				<frame src="${document.URL}" name="mainFrame">
			</frameset>
			<noframes>Your browser doesn't seem to support frames, which is pretty unfortunate.</noframes>
		`;
}

// Change browser address bar to match current page in mainFrame
// window.history.pushState(null, null, document.URL);