Blog directory

I’m pretty new to wordpress. My knowledge of .css and .php is minimal. As such, I’m having difficulty with a couple. My site is http://www.thehelmgallery.com

When you use the hmenu, the active tab has a different background color. This was done using the follow code in the header.php

<li><a href="?page_id=2"<?php if ($page_id == '2') { echo(' class="active"'); }?>>ABOUT</a></li>

and then specifying qualities for the active class. My problem is that my blog does not have a page_id. It is in the root. So there is no way to classify the Blog url because it has no directory. Also, if I wanted to make the About page my front page, I am then unable to access my blog.

There must be a more elegant way to code this, but I am at a loss.