I'm fairly new to html so bare with me...
I have several restaurant websites, adapted from a template. I'll use this one as an example: http://feastaway.com/basic/
You'll see there is a navigation bar, with links to 'Welcome', 'Contact Us', 'Opening Times' and 'View Menu'. The first three are internal links to that section of the page and work like a dream. The fourth one, 'View Menu', is an external link which is supposed to open up a new tab, but when you click it all that happens is it becomes highlighted. It doesn't open the new tab or indeed the link in the existing tab. However, right-clicking and choosing 'open link in new tab' does the trick, so it obviously knows the link is there.
<li><a class="active" href="#welcome">Welcome</a></li>
<li><a href="#contact">Contact <span class="extrabold">Us</span></a></li>
<li><a href="#times">Opening <span class="extrabold">Times</span></a></li>
<li><a href="http://feastaway.com/Campaigns/redir.php?ID=182" target="_blank">View <span class="extrabold">Menu</span></a></li>
</div><!-- end .nav-container -->