Try something like this:
<script language="javascript" type="text/javascript">
<!--
window.setTimeout('window.location="http://www.mywebsite.com"; ',10000);
// -->
</script>
Hi Vinay,
The refresh to open in the current tab is a consequence of your browser's MIME type settings and is controlled locally. You like have PDFs set to open in the native pdf reader of your browser which prompts the tab to navigate to the pdf. If you want to open in a new tab/window there is not a way to do this without getting caught in a pop-up blocker unless you prompt the user to click/interact with the page beforehand. You can get clever with the form onSubmit event, but that might not be an ideal solution.