Jinja2 "class:active"

###in layout.htm, the global template
    <div class="navbar">
		    <div class="navbar-inner">
		    <a class="brand" href="#">KECHB: IsItWeekA.com</a>
			    <ul class="nav">
				    <li {% block home_active %}{% endblock %}><a href="/">Home</a></li>
				    <li {% block about_active %}{% endblock %}><a href="/about/">About</a></li>
			    </ul>
		    </div>
		</div>
		
###index.htm
{% extends "layout.htm" %}

{% block home_active %}
class="active"
{% endblock %}

{% block body %}
	#the body of the page
{% endblock %}