I have a tree View with this code snippet.
I have span with CollOpen or CollClosed class. 
how can i change CollOpen with CollClosed or vice versa on span click that have each of these two class?
     .treeView{
        -moz-user-select:none;
        position:relative;
      }
      .treeView ul{
        margin:0 0 0 -1.5em;
        padding:0 0 0 1.5em;
      }
      .treeView ul ul{
        background:url('http://kaminet.ir/img/list-item-contents.png') repeat-y left;
      }
      .treeView li.lastChild > ul{
        background-image:none;
      }
      .treeView li{
        margin:0;
        padding:0;
        background:url('http://kaminet.ir/img/list-item-root.png') no-repeat top left;
        list-style-position:inside;
        list-style-image:url('http://kaminet.ir/img/button.png');
        cursor:auto;
      }
      .treeView li.CollOpen{
        list-style-image:url('http://kaminet.ir/img/button-open.png');
        cursor:pointer;
      }
      .treeView li.CollClosed{
        list-style-image:url('http://kaminet.ir/img/button-closed.png');
        cursor:pointer;
      }
      .treeView li li{
        background-image:url('http://kaminet.ir/img/list-item.png');
        padding-left:1.5em;
      }
      .treeView li.lastChild{
        background-image:url('http://kaminet.ir/img/list-item-last.png');
      }
      .treeView li.CollOpen{
        background-image:url('http://kaminet.ir/img/list-item-open.png');÷
      }
      .treeView li.CollOpen.lastChild{
        background-image:url('http://kaminet.ir/img/list-item-last-open.png');
      }    <ul class="treeView">
        <li>
            <span class="CollOpen"></span><span>Collapsible lists</span>
            <ul class="CollList">
                <li>
                    <span class="CollClosed"></span><span>Actions</span>
                    <ul class=" CollList" style="display: none;">
                        <li class="lastChild">
                            <span class="CollOpen"></span><span>Actions</span>
                            <ul class="CollList" style="display: none;">
                                <li class="">Expanding/opening</li>
                                <li class="lastChild">Collapsing/closing</li>
                            </ul>
                        </li>
                    </ul>
                </li>
                <li class="lastChild">
                    <span class=" CollOpen"></span><span>Actions</span>
                    <ul class="CollList" style="display: none;">
                        <li class="">Directory listings</li>
                        <li class="">Tree views</li>
                        <li class="lastChild">Outline views</li>
                    </ul>
                </li>
            </ul>
        </li>
    </ul> 
     
    