How to make a li or 'a' '/a' as active when i click

Question

hi i have 3 links in Masterpage like  

<ul>
      <li class="class1"><a href="WorkSpace.aspx" title="WorkSpace">WorkSpace</a></li>
      <li id="WorkQueue"><a href="WorkQueue.aspx" title="WorkQueue">Work Queue</a></li>
      <li><a href="#" title="Reports">Reports</a></li>
    </ul>


suppose when i click on any of the link that should be active (chenge bg color) .

any one help me