AngularJS Example:

HTML

<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<div ng-app>
  <h2>Todo</h2>
  <div ng-controller="TodoCtrl">
   <ul>
<li><a href="#/c/1" ng-class='{"active":tog==1}' ng-click='tog=1'>First</a></li>
<li><a href="#/a/2" class="tree-toggle" ng-class='{"active":tog==2}' ng-click='tog=2'>Second</a></li>
</ul>
  </div>
</div>

CSS

.done-true {
  text-decoration: line-through;
  color: grey;
}

.active{
  background-color:green;  
}

JavaScript

function TodoCtrl($scope) {
  
}