Nasıl Yapılır? Görseldeki gibi Pop up reklam?

<div class="overlay-container samOverlay samOverlay_30 is-active" id="js-XFUniqueId61"><div class="overlay" tabindex="-1" role="dialog" aria-hidden="false">
    <div class="overlay-title"><a class="overlay-titleCloser js-overlayClose" role="button" tabindex="0" aria-label="Kapat">
        </a>Reklam</div>
    <div class="overlay-content">
        <div class="blockMessage">
            <div class="samItem" data-xf-init="sam-item" data-id="30" data-df="true" data-position="javascript">...