Try this:
Code:
<!-- Subforum pull-down menu --------------------------------------->
<form action="forumdisplay.php" method="get">
<input name="s" value="" type="hidden">
<input name="daysprune" value="-1" type="hidden">
<select name="f" onchange="this.form.submit();">
<vb:if condition="$forum[statusicon] == 'new'">
<option value="{vb:raw forum.forumid}" style="font-weight:bold;">{vb:var forum.title}</option>
<vb:else />
<option value="{vb:raw forum.forumid}">{vb:var forum.title}</option>
</vb:if>
{vb:raw forum.subforums}
</select>
<input class="button" value="{vb:phrase go}" type="submit">
</form>
<!-- Subforum pull-down menu --------------------------------------->