Thanks DTA
I'll try that. I have a more advanced version for my .exe download and I'll try this for the pdf.
I also hadn't used the iframe option. I use javascript
<script language="JavaScript">
var deliver = "window.location = '/v2/deliver.php?file=pcpmdemo'";
setTimeout(deliver,10000);
</script>
and this causes no flicker on the window and the download starts automatically.
Because the javascript is at the bottom of the page and there is a timeout the page loads fully.
All of the graphics on the page are cached from the previous page so it should load quickly anyway.
Sarah