<td><center><div class="style4" id="flashcontent">
Om deze gallerij te bekijken heeft u Macromedia Flash nodig.
<a href="http://www.macromedia.com/go/getflashplayer/">
Klik hier om Macromedia Flash te downloaden.</a> Als u Flash al geinstalleerd heeft,
<a href="index.html?detectflash=false">klik dan hier om de gallerij te bekijken.</a>
</div>
         
<script type="text/javascript">         
var fo = new SWFObject("viewer.swf", "viewer",
"900", "600", "7", "#000000");             
fo.write("flashcontent");         
</script></center></td>

It doesn't really make a difference, the space between the gallery and the buttons stays the same. That's what has to become smaller.

Change the 600 in this line to something smaller:

var fo = new SWFObject("viewer.swf", "viewer", "900", "600", "7", "#000000");