For reference, since
X3 release [0.19], you can use the new
modal plugin to display an announcement on page-load. View the modal plugin in action from the demo
sample page (scroll down to "modal plugin").
To use the modal-plugin as a global announcement, you would generally add the following code to main
settings -> footer:
<div id="myModal" class="reveal-modal" data-reveal data-reveal-open aria-hidden="true" role="dialog">
<a class="close-reveal-modal" aria-label="Close"><i class="fa fa-close"></i></a>
<h2>TITLE</h2>
<p>Add your modal content here. Any HTML is supported.</p>
</div>
They key attribute here is
data-reveal-open, which tells the alert-box to immediately open on page-load. Optionally, you could instead use
data-reveal-open-once, which will do the same, but the visitors browser will remember if the modal was opened and make sure it never displays again.