// detectFrame checks for location (in/out of iframe) and referrer (from vincechurchill / elsewhere) and makes visible the appropriate elements on the page
function detectFrame() {
    // checks document for parent containing iframe element; if not found, then page must be out of frame; then makes visible a div containing a banner image and runs check for external referrer
    if (!parent.document.getElementById('framemarker')) {
		document.body.style.backgroundColor = '#000';
		document.getElementById('istage').style.padding = '25px';
		document.getElementById('istage').style.position = 'relative';
        document.getElementById('pff').style.display = 'block';

        // checks document for referring link; if not from vincechurchill.com, then makes visible a div containing a link to the homepage
        if (document.referrer.indexOf('vincechurchill.com') == -1)
            document.getElementById('extref').style.display = 'block'; }}