Only visible in athor:Make sure the desired page to be shown in the iframe contains this script-tag:
<script src="https://www2.telenet.be/content/dam/www-telenet-be/templated/modules/resizable-iframe/src/iframeResizer.contentWindow.min.js"></script>
Info window:
Page in iframe: https://mkt.telenet.be/optiext/optiextension.dll?ID=QtSQwhpHnhtP8jkjpYlbGTLkgEro6eEEbk4ZWuxo4up5lw5CF2pRMAHL69NITAk1FnTvKxaJzSiQQr
