Hi,
I think I have sorted it by looking through the forum at other posts and solutions
I found this post:
http://www.silverstripe.org/template-questions/show/251612#post251612
and finally I used the following, hopefully correct:
<ul id="topmenu" class="sf-menu sf-navbar">
<% control Menu(1) %>
<li <% if LinkOrSection = section %>class="current"<% end_if %>><a href="$Link" >$MenuTitle</a>
<% if Children %>
<% if URLSegment != what-s-new %>
<ul>
<% control Children %>
<li><a class="$LinkingMode" href="$Link" title="Go to the {$Title} page">$MenuTitle</a></li>
<% end_control %>
</ul>
<% end_if %>
<% end_if %>
</li>
<% end_control %>
</ul>
Thank you very much for all your help NickJacobs, I really appreciate it.