Vertically center swf file

Hi all,
This is probably a stupid question, but I can’t figure out a way to get this to work! I have a small swf file, (sized 300x237), and I would like it to center itself on my webpage. There’s a little piece of code in the embedding script that centers it horizontally (align=“middle”) but I can’t figure out what code to use to center it vertically on the page. I’ve tried valign=“middle” and valign=“center”, and neither work. But I don’t know what else to try, I don’t even know what type of script it is. Here is the the part I’m referring to:

<object classid=“clsid:d27cdb6e-ae6d-11cf-96b8-444553540000” codebase=“http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0” width=“300” height=“237” id=“index” valign=“middle” align=“middle”>
<param name=“allowScriptAccess” value=“sameDomain” />
<param name=“movie” value=“index.swf” /><param name=“quality” value=“high” /><param name=“bgcolor” value="#ffffff" /><embed src=“index.swf” quality=“high” bgcolor="#ffffff" width=“300” height=“237” name=“index” valign=“center” align=“middle” allowScriptAccess=“sameDomain” type=“application/x-shockwave-flash” pluginspage=“http://www.macromedia.com/go/getflashplayer” />
</object>

Thanks for your help!