Pearls of MOSSy Wisdom

On the page you want to show this message, put a Content Editor Web Part on the page. Edit the Source (not the Rich Text) and paste the following:

<DIV style="position:absolute;z-index:1000;background-color:white;width:100%;height:100%;top:0;left:0;opacity:0.9;filter:alpha(opacity=90)" id="pleaseWaitMessage">
<p style="text-align:center;margin-top:200px;color:black;">
<img src="/_layouts/images/ewr133.gif">
<br>
Loading... please wait.
</p>
</DIV>
<script>
function hideMessage() { document.getElementById("pleaseWaitMessage").style.display = 'none'; }
document.onload = hideMessage();
</script>